A recent survey by Tableau Software has concluded that iPad users in the US are lucky enough to pay for the fifth most expensive iPad data plans in the world—“lucky” meaning, at $12.50 per gigabyte, we’re not paying the rates of the top four.

Users in France pay the local telco, Orange, the most for their iPad data plans. At $25.47 per GB, their rates are over twice that of AT&T in the US. Users in Belgium and Luxembourg pay Mobistar $21.77 per GB and users in the Netherlands pay an average of $19.58 per GB to either Vodafone or T-Mobile.

The cheapest rates are available in Singapore, where users may pay as little as $.51 per GB. Users in Hong Kong, Germany, Japan, Italy and Austria all pay less than $1.50 per GB. This may be due to the fact that, in many of these countries, iPad users have more than one option for their data carrier. Of course, that didn’t help the Netherlands.

You might think gardens would escape the gold and diamond trend endemic to “most expensive” objects. You’d be wrong. While supremely expensive and completely organic gardens do exist, so too do gardens bejeweled for millions of dollars (or, in this case, euros).

Leonardslee Garden – $7.62 million

Leonardslee Garden in West Sussex is a lush, 225-acre property filled with beautiful flower gardens, wallabies, lakes, waterfalls and one-of-a-kind trees. The gardens are filled with rhododendrons, camellias, magnolias and azaleas and the forty-strong mob of wallabies, many of them albinos, keeps the gardens from being overgrown with weeds.

The garden has been owned by the Loder family since Sir Edmund Loder bought the estate in 1889 and it has been open to the public for 101 years. That all changed in 2010, however, when Robin Loder, representing the fifth generation of Loders to tend Leonardslee, sold the gardens for a grand sum of £5 million—US $7.62 million—to an anonymous buyer who wished to discontinue public access to the gardens.

This isn’t the first part of the original estate to be sold, as the Loders sold the Italianate manor in the 1980s. It’s currently for sale at £2.75 million—US $4.2 million—and it’s been speculated that the same billionaire has set his sights on that property as well.

Ace of Diamonds – over $31 million

The Chelsea Flower Show, held annually by Britain’s Royal Horticultural Society, is the world’s premiere horticultural event. Over the course of five days in May, some of the most fantastic floral and vegetable gardens, as well as tree exhibits, are on display on the Royal Hospital Chelsea grounds. The 2010 show was no exception and included the most expensive garden in the world.

Designed by renowned landscape gardener David Domoney, the Ace of Diamonds plot is the ultimate fusion of plant life and precious gems. The garden boasts both plants named after jewelry and jewelry inspired by plants, including such plants as ‘Juniperus Emerald Spreader’ and ‘Pulmonaria Opal’ alongside jewelry such as a daisy shaped ring set with a rare $5 million blue diamond.

Tomboy turned fashionista Kelley Dooley knows it’s hard for women to find fitness wear that looks good, which is why she founded BodyRock in March 2009. Browse her shop and you’ll see collections with names like “Keep ‘em In” or “Lock ‘em Down.” You’ll also find the most expensive sports bra in the world.

The Trenta Bra is made with black spandex and gunmetal burnout fabric, which helps to ventilate, with black diamond Swarovski crystals along the neckline. The true-to-size bra also incorporates gunmetal sterling silver jewelry from Knight & Hammer’s Trenta collection, which can be detached from the bra and worn as either a long necklace or as a necklace and bracelet. It even features an open pocket on the back.

This luxury sports bra can be purchased online for $1,850 and comes in sizes ranging from XS to XL.

Google’s Android mobile platform has made some waves since it was announced in 2007. As of May 2010, Android claimed 13% of the market share of smartphones in the US—over half of that claimed by the iOS platform run by Apple’s seemingly ubiquitous iPhone. One of the great advantages Android has over iOS is that it isn’t married to a particular hardware manufacturer, allowing many different companies to try their hands at Android smartphones.

The Chairman by Ulysse Nardin is one example of such a phone. Billed as the “world’s first luxury hybrid smarthpone,” the Chairman includes both a touch screen and a physical number pad. The Ulysse Nardin name is most often associated with luxury watches and that fact shows in the Chairman’s sophisticated design. The volume controls look like watch buttons and the crown between them can actually be wound to generate power for the device. In fact, the phone features a kinetic rotor power system visible through the backplate.

As for its hardware specifications, the Chairman has 32 GB of internal memory, an 8 megapixel camera, a Freescale i.MX processor and a display capable of high definition video playback.

There are five versions of the phone, made using either steel or 18k rose gold in the frames. Only 1846 units of each model will be produced. At a staggering $12,800 to $49,500, it’s the most expensive Android smartphone in the world.

What is the most expensive city in the world? Before you can even begin to answer that, you must first decide what “most expensive city” actually means. Several companies have done just that over the last few years and, due to the different methodologies used, compiled lists with surprisingly different results. We’ve compiled our own list of some of these surveys and the cities they’ve concluded are the most expensive cities in the world.

Mercer Cost of Living Survey, 2010
Highest-ranking city: Luanda, Angola

Mercer’s survey compares the costs of over 200 items in each of 214 cities. The survey covers the cost of housing, food, transportation and other essentials to help employers determine compensation for expatriate employees. This is the first of Mercer’s surveys to include African cities Luanda, Angola; Ndjamena, Chad and Libreville, Gabon. The high placement of these cities in the survey—Ndjamena placed third and Libreville placed seventh—can be explained by the fact that these areas, while rich in natural resources, are generally poor and expatriate employees must rely on newly built infrastructures. Other high-ranking cities on Mercer’s survey include Tokyo, Japan in second place; Moscow, Russia in fourth place and Geneva, Switzerland in fifth place.

Economist Intelligence Unit Cost of Living Survey, 2009
Highest-ranking city: Tokyo, Japan

Unlike Mercer’s, EIU’s survey disregards the cost of housing as it is usually provided by expatriate workers’ employers separately from their wages. The result is a list that may be more useful to the expatriate employees than to their employers. This list places Oslo, Norway in second place; New York City in third; London, England in fourth and Sydney, Australia in fifth. Luanda is notably absent from the top tier.

ECA International Cost of Living Survey, 2010
Highest-ranking city: Tokyo, Japan

ECA’s survey also disregards the cost of housing, as well as utilities, vehicles and schooling. In their survey, Oslo, Norway places second; Luanda, Angola places third; Nagoya, Japan places fourth and Yokohama, Japan places fifth.

To a collector of model cars, a model of the Bugatti Veyron might be the centerpiece of their collection. It is, after all, the world’s most expensive car. Of course, for the truly dedicated—and well off—collector, the only option is the world’s most expensive model car.

The Bugatti Veyron Diamond Limited Edition, a collaboration between luxury designer Stuart Hughes and Swiss model car engineer Robert Gülpen, is a 1:18 scale replica of the ultimate luxury car, rendered in 24k gold, platinum and 7.2 carats of single cut flawless diamonds. The hoods and steering are functional and the engine is highly detailed. This fantastic model car weighs in at 15 pounds and took two months to produce.

Only three of the most expensive model car in the world have been created, each accompanied by a certificate of authenticity, glass house, aluminum case and photographic documentation of its manufacture. Even more phenomenal, the Bugatti Veyron Diamond Limited Edition costs twice as much as the car on which it is based—US $3 million.