You need to ask Matthew that 
I believe he's aiming it around the £70-£80 mark.
Just to be clear, though, it's NOT a general purpose sound card, it's a streamed audio player (i.e. MP3/OGG/FLAC/WAV). It's great for playing really good quality music (high-bitrates are supported) though.
Sounds pretty cool to me! Definitely going to get one, so will start saving up some £'s right away.
