The previous answer ignores a number of very good alternatives which much better pricing than the machines from Razer and Alienware where you pay a great deal just for the name. For example, Alienware used to be the name everyone thought of for premium gaming machines. Since being acquired by Dell, however, their quality has gone down a bit and their support has gone down substantially, without any real change in price. So you still pay the premium price without getting the premium hardware and service they used to provide.
In particuler, MSI makes a very good line of gaming laptops.
A secret of the gaming laptop world is that many of them are made by the same manufacturer as "bare bones" machines and then completed by different vendors. You can do the same thing yourself and get exactly what you want instead of dealing with some other company's profit margin. Just search for "bare bones laptop" and you will find people offering these as well as the means to equip them as you choose for a truely custom build that you will know inside and out (since you built it).