Getting a Mark II/III for less than $300 is great if you can get one. Getting any quality gun, in fact, for just north of $200 is quite a feat, too.
The prices of guns are going up at a frightful pace, and even if you find a gun on an auction site, you still have to pay for shipping and for transfer. Something else to consider is that Rugers keep their value well because they almost never need parts replacements. So getting one for $250 would be a great deal. (I have a stainless Mark II with a 7-inch barrel that I'm very fond of. I also have an AMT Lightning that's also very nice.)
The Standard Auto is a great gun for the nightstand, and they have a good balance. The adjustable sight versions are good hunting and target pieces.