Half or full lug? Used to be those Canadian DAO GP's were everywhere, I got mine 2 years ago for like $300 and now it seems you hardly see them........
I hav several 4" fixed sight GP100's, and I love them. I have both .38's and .357's. They are everything you need in a fighting revolver and nothing you don't. My blue half lug .357 4" fixed sight GP100 with the large Lett grips is one of my favorite handguns.
Ruger was selling an "over run" of the blue half lug .38 4" fixed sight GP100's about a year ago, there's probably a few floating around on GB.