Luxury resort complexes are expensive to stay at not for some arbitrary attempt at exclusivity; they cost a lot to build and maintain, meaning and owners have to charge visitors enough to justify their upfront investment and ongoing expenses.To give you a sense of how much cash is being put on the line whenever a new resort opens, here are a few global hotspots that had the biggest price tags attached to them during development. Abraj Al Bait, Saudi ArabiaNot only is this complex of seven skyscrapers in Mecca imposing because of its scale, with the largest tower topping out at 601 meters (1972ft), it also features a five-star hotel which is the tallest hotel in the world.In total it cost $15 billion to construct and is also in great demand amongst pilgrims who travel from around the world to visit this holy city in Saudi Arabia.Interestingly enough, although this was a publically-funded project, the hotel, and resort within it is operated by Fairmont, a Canadian firm known for its luxurious locations in 24 different countries worldwide.Known as the Makkah Royal Clock Tower, there are nine different restaurants, a rooftop bar and easy access to an incredible 4000 different shops. Of course with fast internet access, guests can entertain themselves during their stay, and Casumo NZ has a big selection of games for this very reason.source wikimedia.orgCosmopolitan of Las Vegas, USASince opening, the Cosmopolitan has become the most popular five-star hotel that Sin City has to offer, eclipsing all of the competition thanks to its incredible array of features split between the two towers which make up the resort.Deutsche Bank backed the building of the Cosmopolitan, forking out over $4 billion in the process. The fact that it failed to make its money back and ended up selling the resort shows that it is harder to run a successful casino complex in Vegas than many might think.Of course, the Cosmopolitan is very much still open for business and is regularly ranked amongst the best hotels globally, boasting 3000 rooms with the most opulent features available, along with a spa, a vast theatre, a convention center and of course an especially classy casino. Marina Bay Sands, SingaporeSingapore is a city of light, sound, and luxury, all of which are epitomized by its most iconic hotel complex.The Marina Bay Sands enjoys a waterside location and is made up of a trio of towers, all of which are interconnected by the incredibly rooftop ‘Skypark’, which is a great place for a stroll, a drink or simply to gaze in awe at the mega-city surrounding it.When it comes to the nitty-gritty of price, the site on which the resort is situated cost $1.2 billion alone. On top of that, construction costs were initially projected to be almost $3.9 billion, although delays to the opening and material shortages eventually increased this to over £5.5 billion. As it generates around $2.7 billion annually for Singapore’s economy, this investment was definitely worth it. Emirates Palace Hotel, Abu DhabiAlthough it is one of the more affordable luxury resort complexes on this list, the $3 billion price tag of the Emirate Palace Hotel is still a significant chunk of change by any measure. It also stands out because its design is more traditional and it aims to impress visitors not by being the tallest or most feature-packed place, but rather by making every square inch speak of wealth and power.The hotel also plays something of a cultural role, with art exhibitions and theatrical performances frequently taking place within its reassuringly solid walls. All of this helps to make it a luxury resort with a difference.