Nowadays, SP games won't cost much. But, you can easily find sp games at game stores at any EB Games or GameStop for as low as $2.99. So my guess would be, anywhere from $.99 to $4.00, depending on the game and how new it is.
about 5-10 dollars
That is impossible, since Game Boy Advanced came out after Game Boy, also, the Game Boy Advanced game cards are much shorter (about half the size).
about 50 - 60 $
20 $
No, you can't. Super Game Boy is only compatible with Game Boy and Game Boy Color games.
a good fiver
The Game Boy Micro is a GBA and plays GBA games, but does not support original Game Boy or GBC games.
Yes. You can play Game Boy, Game Boy Color and Game Boy Advance games on a Game Boy Advance SP.
Yes they are much better.
Yes, you can play Game Boy Color games on a Game Boy Advance. All Game Boy games, including Game Boy Color games, are backwards compatible with the Game Boy Advance.
well it all depends on the condition of the "game boy", I got mine for $20 because it was a limited edition game boy, it all depends on the condition and the edition of it. A good place to get a good low price game boy is "games n'go".
Game Boy Games can be played on both the GameBoy Advance and the GameBoy SP.Game Boy and Game Boy colour games can not be played on a DS though -through the carriage slot.