I would consider a real Colt. I have had 1911s for 15 to 20 years, from Norinco to very high end custom-built Caspians. Last Dec. I bought a clean, unmodified Series 70 Colt off an auction for around $525 delivered. The only negative was some blue wear from oily fingers on the front grip strap, a bonus was the faux ivory Colt grips. This was a great price, but other good deals are possible under your limit. It has seriously become my second favorite 1911 (next to one very high end Caspian). Very high quality, very reliable (100% so far). I see good ones on GB and AA from 600 to 700 frequently.
There is something to be said for the real-deal Colt. The only negative is the mil-spec sights, but I wanted it stock. Another good deal is a Norinco. I bought one NIB in like 93 or so and it's going no where. I saw a very nice boxed one for like $400 in the classifieds here or at THR. They are very reliable, great steel quality, have high-profile sights instead of mil-spec, and are good platforms if in the future you want to build a custom.
Another good strategy is to check auctions and see if you can find a custom built Caspian by a good gunmaker. Caspian components are second to none - mated to a good barrel from Bar-Sto or Clark or similar built by good hands and you have a piece of art.
Here's some eye candy to tempt you into the Colt.
