Ohh boy... LOL. I collect manga, if that counts. But then again I'm young and can leech off my parents for cash. LOL. My absolute favs are:
Petshop of Horrors
Chobits
YGO (o.o don't shoot!)
Shonen Jump
Yuu Yuu Hakusho
And I love, Love, LOVE the League of Extraordinary Gentlemen. It's the ULTAMATE Victorian literature crossover fiction-type thing. Plus the fact that the movie could be called LX-Eyecandy.
GNs are just illistrated novels. Manga, comic books, but not the tiny thin ones. GNs almost always have enough pages to be considered a novel.
And yeah, it isn't just in Poland where they're expensive. A regular manga book, depending on the company printing it, is usually anywhere from $10.00 to $15.00 dollars in the States. It's because alot more work goes into them. There's not just a plot and dialoge, but it takes alot of work and talent to sit there and draw the entire book out, and then some of them are colored. So depending on your opinion, the extra cash can be worth it. Alot of it is opinion, though. Like my parents for whether or not they'll pay for more comic books for their kid, LOL.