If it is basically new, with no scratches or wear and comes with all the usual stuff: Box, mags, loader, brush, papers etc then 300$ is fine.
Its not a screaming deal, but why quibble over a few dollars. The gun itself is as good as many guns that cost well over 400$ and it compares well to high dollar guns.
Consider that it is about the same size, weight as a Sig P226, is equally as reliable and at 25yds or less is going to be similar in terms of "practical" accuracy.
Note, that is different from Absolute accuracy (bench rested or machine rested using a Ransom rest), in that category, something like a Sig will probably smoke it. But in terms of practical Can-you-hit-a-pie-plate-consistently type accuracy a P95 is pretty darned good. A P-series gun will usually group about 3-6in@25yds which is good enough for most purposes.
The Sig is going to retail for...well, I dunno...Lots $$$ maybe 800$ I dont really keep track of Sigs because they are so expensive.
Point is that a P95 is very good bargain at 300$.