500's a good sized budget. For that kind of money you can get:
Win 94 in 30-30, 32, 375, 444, ?
Marlin in 30-30, 35, maybe even 45/70 or 450.
Blr, most likely in 308.
Personally I'd take a win over a marlin any day of the week, twice on sunday.

I'd take a blr over a win, too, even though J. Browning designed them both.
Marlin's iron sights suck, which is why you see so many used one's with those darn peep sights or some other aftermarket sight on them.
That being said, you realize for another 100 and change you can buy a brand new marlin? I'd personally take 2 used win. though.
Being serious, you really can't go wrong with any of them, and you're budget is large enough to have a choice of any of them, and in VERY good shape, so be picky if you buy used.