If you are looking for some range only mags to save wear and tear on your standard capacity ones, or are in a 10 round state, CDNN has 10 Round Magazines for $19.99
These will work in your USP Compact 9mm, P2000 9mm or P2000sk 9mm (though the magazine body will stick out the bottom of the P2000sk a bit).
I just got a few in from CDNN for range use. Brand new in the HK factory bag.
A used P2000 I purchased a while back came with a couple and I use them for the range. They work just as well as any other HK mag. I decided to grab a couple more while they were cheap. Just a heads up, these are about $15 cheaper each than other places have them for.