In the 1980's, revolvers were more expensive. And autos were about the same if not slightly cheaper. Typically $500-600. I noticed in the 1990's that the prices of revolvers fell, while some autos went up in price and others stayed around the $6-800 range.
Colt Python revolvers have always been expensive. But that's a lot of hand work to put it together and polish it up so nice. I imagine its the same with 1911's: if you want inexpensive, you can find Chinese, Philippines, Turkish and Brazilian 1911's that function decent. But if you want top fit and finish, you'll spend much more or do the work yourself to pimp it out.
One thing to consider is that the manufacturing processes for one 1911 company may be different from another. Tech has changed, and some newer processes are cheaper, others provide better parts, but the machine may not be affordable to another mfg. CNC milling and turning for instance, may not be used by the bottom end manufacturers (dunno why though).