That is an average to middle of the road price. Its fair if you have to have one but it is not a great price. That being said, there are exceptions depending on the year and make.
I just picked up a 92 made in Belgium assembled in Portugal HP for $360.00, NRA excellent. Had to shop, went to a lot of gun shows and spoke to a lot of people, but found this one in about six months of looking. I have seen a lot of acceptable HP's out there in the $425 to $450 range.
There are generally two broad categories of HP's. Those that have collectable value and those that are shooters.
Depending on the serial number you may have one with some level of collectable value or some unique characteristic that would increase the value.
If you are looking for a shooter and you are not in a hurry, keep looking.
Make sure you take a look at
www.fnhipower.com
There is a wealth of info there and a lot of friendly knowledgeable folks who are glad to help a new inductee to the world of HP's.