$500 is an ok deal considering they didn't sell well. Is it steel or alloy? I am pretty sure they were made in both. That may also affect your decision.
Like the others said, if you can test it and it functions well, and you can get the price down a bit, I'd get it. Make sure to check out the feedramp. I had a Para Companion that had a very rough ramp. I just got the Para Carry and it shoots like a dream. I liked the Para carry because of the thinner grips and didn't like the P10 because of the thicker grips. I do have the P12, 13 and 14, so I really like Para's, but passed on the P10.
Another thing is if you are going to use this for daily carry, sometimes the thigh grip is harder to conceal. I had a tough time trying to conceal my P12, so I bought the Para Carry.
10+1 on the P10 is a hard deal to pass up though. Let us know what you do.