E.R. Shaw makes good barrels. Douglas makes a better product. Brux is better still. Yes the price goes up with quality. There are many more mfg of "drop in" barrels.
How much are you looking to spend? A stainless Shaw will be about $180+. The Gun Shack had some around that price. $250 for a Douglas at thier web site. Sharp Shooter Supply has brux barrels about for about $365.
Edit** $200 for the Shaw, $289 for the Mcgowin, $320+ for the Douglas, and $440+ for the Brux. It had been a while since I've done price checks. In this situation price reflects the extra work that goes in to making a quality barrel.**