$480 at an LGS where you don't have to pay shipping and transfer fee is fair in my opinion. Not a smoking deal, but fair. I got a police trade in USP 45 full size back in 2013. I replaced the dim night sights with new ones and installed a LEM kit. I really like the gun. It is a pleasure to shoot.
I have since acquired a USP 9 full size (converted to SAO), a USP 45 compact (installed LEM kit), a HK45T (factory LEM), a P30 (factory LEM), and I just got a VP9.
The only legitimate criticism of the USP45 in my opinion is the grip size. I have large hands, so I like it. I think the bottom line is that if you want a true double stack 45, the grip will be large. Compare the Glock 21. The KH 45 is staggered, and they managed to make the grip smaller by reducing capacity to 10 rounds. No free lunch. If you are used to Glocks, the bore axis is relatively high.
What I really like about H&K pistols is that they run. I don't think I have ever had a stoppage in any of mine.