Buying a car, especially a new car, is actually relatively cheaper in Dubai than in many other parts of the world. The initial purchase price tends to be cheaper (according to expatarrivals.com, which gives advice to expatriates planning to move to Dubai) than it would be in the US or UK. There are many dealerships and services available in Dubai to purchase a car, so costs for both new and used vehicles are lower on average and are usually negotiable. Registration costs are about 500 dhs, though more services are available to expedite this process and can increase that cost.
The cost of actually operating a vehicle in Dubai is really not all that high either. Maintenance costs tend to be relatively low. Insurance is mandatory for getting a car registered. Rates depend on many different factors including driving history and the vehicle in question, they are usually not prohibitively expensive. Since the UAE is an oil-exporting area, petroleum costs tend to be relatively low as well. In recent years, the most popular types of vehicles in the UAE have been small family cars, which tend to be inexpensive to buy and maintain, and, since many of these are also on the used market, it is generally not very hard to find an affordable vehicle.
It is difficult to factor into the cost of owning a car in Dubai, but this area actually has a very high crash rate. “Fast cars combined with drivers from many different nationalities” (dubaicarprices.com) mean that the roads in Dubai, though generally exciting, can also be quite dangerous, so it is worth considering the likelihood of having an unavoidable car crash.
Though maintenance is usually not terribly expensive, certain harsh environmental elements in Dubai mean that it must be done more regularly. Heat and sand can destroy mechanics and the interior of a car, reducing its overall value, though steps can be taken to reduce this.
On an interesting note, some cars actually tend to appreciate in value over the first few years of their operational life in Dubai. Dubaicarprices.com mentions the case study of the Hummer H2, which has increased in value lately due to its popularity and the fact that is relatively easy to maintain (though petroleum costs must also be considered when driving such a Goliath.) This is far from the norm though, and it should not be assumed that vehicles will not lose value while you drive them.