There are 2 frames to choose from (traditional and 22/45) and many barrel options. Add in the different finishes and grips, and you get dozens of combinations. I was recently searching for my second mkIII, and I was shopping for the bull barrel with traditional grip angle. You can find a traditional or 22/45 blued model with a target barrel or the bull barrel around here for under $350, unless you add laser grips or other high-end goodies. Stainless adds a bit to the price. The standard model (tapered barrel, fixed sights) runs just under $300.
Don't discount the used mkII market, they are tough pistols with plenty of Ruger and aftermarket support, so there isn't any real reason not to purchase a used mkII in good condition.