I'm selling my DS-10+ copy, 'cause I don't own an US-DSi, and I don't need the improved song mode.
Bought new for $35 at play-asia.com, mint condition, will sell for... uhm... dunno... let's say $25 + shipping costs? Also looking for guitar FX (delay, filter, flanger, stuff like that) or a fully functional Gameboy Advance. Offers are welcome.

