After spending way too much time on YJA and eBay, I eventually realized that YJA seller "barofever" has some of the same albums for sale that champs has. Comparing a few items side-by-side shows that the two sellers' pictures are actually identical, which strongly suggests they're the same person. A few examples of this are below.
I guess this means that if you're buying from champs, it might be worth seeing if barofever has the same item cheaper, as the prices aren't identical.
Panzer Dragon II Zwei
Athena the Music