These days, most of what you see on Gun Broker is brand new stuff offered by discount dealers. It's actually hard to find a used rifle for sale by a private individual. A few pawn shops have some used rifles now and then. But mostly it's places like Bud's and Northern Firearms advertising bolt actions.
I haven't kept up with the latest opinions on Remington bolt actions. Back in the day, Remington and Winchester rulled the roost on good quality decent priced bolt actions. Things have been changing so fast in regards to Remington, I don't know what to think anymore.
It would be hard to beat a Savage in terms of a good accurate bolt action .223 though. They come in Model 10, Model 11, Model 12, Model 14, Model 16, and Model 16. Also, the Stevens is basically just a Model 10 in cheaper clothing. I'm not too fond of the Edge or Axis models though in the Savage lineup. If it were me, I would get a Model 14 if I liked fancy wood and nice looks. I would get a Model 12 or 25 if I wanted a good varmint or target shooter. Look on Gun Broker and you'll see a couple hundred new Savage bolt actions in .223 caliber.