With your budget you could build a killer rig. I know you said you want to get something off the shelf, but I highly recommend building your own. It's not as tough as it may seem and you will save money over buying the same thing pre-built. You can easily build yourself a great rig and have money left over - and I'm betting your wife would love that.
and just because you build it yourself does not mean it is not covered.
ALL of your components will be covered under manufacturer warranty.
A lot of Power supply manufacs are offering 3 or 5 yr warranties. DON"T go cheap, THE POWER SUPPLY IS THE SINGLE MOST IMPORTANT COMPONENT. based upon the Alienware config....1000W+ PSUs range about $160-$600, DO NOT buy a $200 one, stay in the $400+ range You get what you pay for. Buying a cheap one can end up damaging other system components like the video card, CPU or Motherboard, I would HIGHLY recommend PC Power and Cooling or check JonnyGuru.com and find a 1000W that he has rated at least a 9
EVGA and XFX offer lifetime or even double lifetime warranties on Video cards.
Western Digital covers hardrives for 5 yrs.
Gigabyte Motherboards are covered for 3 yrs
everything else will be warrantied for at least a year maybe upto 3 depending of the maufac.
With prebuilt machines they offer a 1 yr warranty usually with the option to buy an extended warranty. so they are charging you for something they get for FREE, they get the same manufac warranty you do.
I would also find out where Alienware services warranty systems. Do they have a local approved service center or do you have to ship back to them???
BTW....glad you decided to buy a new system rather than trying to upgrade the old one. you'll be much happier and if you got a budget $3k you won't be hitting any gaming walls for a while.
as CommanderAdama suggested feel free to PM me and I'll give you my IM or email. be happy to help if you want to build your own.contact one or both of us.
Building your own is very easy, you'll enjoy the system more knowing you built it.