I have a couple Springfield P-9's, one "standard" and one Ultra. Got a great deal back when they were closed out (might have been CDNN?).
I'm pretty fond of them. I'd agree with Peter. They are the most accurate .40's that I've shot, and put the lie to the idea that the .40 S&W is "inherently inaccurate". I bet you're looking at a standard if it has wood grips. Mine does not have a compensator and I don't think the gun was produced with one.
I like the SA/DA trigger. It does offer a second strike capability if you encounter an insensitive primer. The safety is where John Browning intended it to be positioned. Both of mine have 4# SA pulls, both smoothed up by Teddy Jacobson. The triggers are good, but not the equal of a tuned 1911 trigger.
My 19th edition Blue Book says the gun was discontinued in 1992. For a stainless standard P9, they quote $425 for a 98% gun and $350 for a 95% gun. I'd would happily pay that for the gun if I didn't have one, and don't think I'd sell for that price.
Extra mags may be hard to find. I fortunately grabbed several extra when I bought the pistols.
Anybody know why Springfield dropped the pistol? Just poor sales? My only caution is to keep it clean. I've twice had my standard model get a squirrely trigger where it would occasionally drop from cocked to a half-cock when gently pressed. Cleaning out the trigger mechanism solved the problem. The Ultra has never done this.