I'd agree with a 1 in 3 hit rate on the American Standard Fenders - maybe even 1 in 4 or 5. When you do find a good one though, they're really, really great. For your budget you could wait and get a US Standard from someone on here. While pretty rare, they do occasionally come up and sell at your kind of budget.
Plus if you go second hand and you got bored with whatever you bought and wanted to sell it, you'd more or less get your money back.