I was at the gun show today here in h-town and was offered a SP1 (pre-ban) upper for $220.  It was in pretty damn good condition, didn't have a bolt, carrier, or charging handle.  

Is this a good price, and how much will a pre-ban lower run me?  

Any thoughts or suggestions would be greatly appreciated.  

Very good price on the upper. If you plan on a nice Colt Pre-Ban to go with it you'll be looking at a grand or better.