Pretty much just scale down the settings.
However, considering I have a £350 machine thats over a year old, (about $500 I think), and it's doing me just fine, I'm in no rush to go remortgage to buy an Alienware right now.
Honestly, I think the gamer PC market is just silly, everything seems SO far ahead of what's actually needed to play modern games. Why future proof your new machine when you can just add components when you actually need to, knowing that by default, they'll be far cheaper than a year ago?
I think many of us are altogether far too obsessed with benchmarks and frames per second. If it looks ok, stop fiddling with it and enjoy life. (a life lesson that applies to many things.)