Hi LU! Is there a particular reason you're after Red or Blue Furies specifically? Reason I ask is you can pick up very reasonably-priced Bitfury-based USB miners at either
my store (if you're in Australia) or the
Hashrate Products store (if you're anywhere else in the world).
I hope this didn't come across too sales-pitchy. Definitely look around to see if you can get a better deal; I'm pretty sure we have the best prices available. Also, if you've got any questions about the units please don't hesitate to ask either myself or the guys at Hashrate. Always happy to help!
Cheers,
bitgtr