My go-to hunting rifle is a 99C in .308
$700USD is a pretty standard price for a Savage 99, but I'd see if you could talk them down 10% just because the detachable magazine version isn't nearly as sought-after as the internal rotary ones, and a 99 chambered in .308 is actually pretty common.
I've never had any feed or ejection issues, but the lever tends to be pretty firm when chambering the first round.
I also wouldn't worry about buying a second magazine for a couple of reasons. The magazine that came with the rifle is going to have the same amount of years and wear on the finish, so it'll match better than a replacement, and in any case there are so few scenarios where you'll need a spare magazine anyway, especially if it's going to be used for hunting. Plus you can top off the magazine through the ejection port; you'd be surprised how easy this is. For target shooting it could be a different story, but with the steel butt plate it's good to give your shoulder a break between every 5 rounds.
Hope that helps!