Depending on condition, I'd say that anything between $300-$400 seems to be the going price.
I don't see the price of these guns going up or down at all, but I can see them, and their more finished 39xx brothers becoming harder and harder to find.
If you are in the market for a compact, single stack, 9mm, I suggest you pay the asking price as long as it is relatively reasonable. Forget what the gun "sold for back in the day". This is the Obama economy, and it's worth what it's worth, simple as that. I do like to haggle a bit myself, and always feel like I get a "deal" if I can at minimum, get the dealer to roll the taxes into the shelf price. (I.e. Make a gun listed at $399.99 6% less if there is a 6% sales tax, so I walk out paying exactly $399.99).
Good luck. Nits a neat gun.