I've read multiple post here on GJ about sticking to the $1/pound for vises, but I am assuming it doesn't apply to the C series Wiltons or Reeds?
A wise man once said you can have it good, quick, or fast, but not all three.
If you cruise Craigslist 10 times a day for a year in maybe a 25 mile radius of a major city you MIGHT find a nice Wilton C1 for $60. But a couple of other guys will probably already be in their trucks on their way to pick it up.
If you greatly value your time, you can get a nice Wilton C1 for around $500 just about any time you want. Or get a high quality fixer upper vise and do a lot of work on it.
Your choice
You can read GJ stories about guys lucky enough to find almost unbelievable deals on Reeds, Wilton bullet vises, etc but nobody lists the hundreds of hours or hundreds of miles involved in fruitless C/L searches, dead end garage sales, or wandering around flea markets to uncover those few gems.
If you're not in it for the thrill of the hunt, I recommend just buying a nice vise at the going price and be happy.