Obscure: Who Remembers TSA? Rarest Album?

Here's one for the memory bank. Who remembers TSA from Poland? The band formed right at the dawn of the 80s and was actually an instrumental act. In short time, the band snagged a singer and started releasing albums and to date has released several studio works. I think their most famous work is Heavy Metal World (English version released in 1985). The band is active and is currently playing gigs, but the website doesn't have an English translation so I'm not confident posting what I could make out (and believe me, I couldn't understand much). Maybe some of our friends in Poland can fill us in as TSA is one of the biggest bands from that part of the world. If you haven't guessed, I think it's cool to post about bands from all ends of the earth.
Here's the band doing "Heavy Metal World" in 2005 (in English).
Writing about TSA sort of got me wondering: what is the most obscure glam or metal band out there that people just rave over? You always hear stories of people spending a couple hundred bucks on a rare vinyl or CD, but I've never been able to peg the most sought-after rarity. Just something to ponder.