you have got a good setuo but you over expended seriously alot.
Also your setup is awesome for now but it wouldn't last after 1.5-2 years cause you didn't get direct X 11 supported card and you have got a duel SLI GTX 295 when Nvidia is already offering Quad SLI GTX 29X.
If you were gonna spend so much then you should have bought TELSA GPU from Nvidia which twice as good as your current one.
You shouldn't listen to the Alienware executive,they will always try to rip.Also they don't know that much about new tech,they only know about whats available with them.Next I would recommend you to do some more research.
I have a $1500 with Core i7,8gb ddr3 ram,2gb Telsa Nvidia,1TB SSD,21 inch monitor which can easily beat your configuration