There are two 3rd party guitar hero controllers (dunno if they work with Rock Band) in DX.
They're probably not as good as the official and Datel ones, and they are more expensive, but it may come out cheaper, if you include the shipping cost.
PEGA Wireless Guitar Controller
Crazy Guitar Controller
Anyway, I have an official guitar for the PS2, and I now got a PS2toUSB converter, so I'll check if it can play on Guitar Hero/Fun on the Wii. Probably not, but worth trying.
They're probably not as good as the official and Datel ones, and they are more expensive, but it may come out cheaper, if you include the shipping cost.
PEGA Wireless Guitar Controller
Crazy Guitar Controller
Anyway, I have an official guitar for the PS2, and I now got a PS2toUSB converter, so I'll check if it can play on Guitar Hero/Fun on the Wii. Probably not, but worth trying.