Following the closure of DM (www.unicycle.co.uk) earlier this year, I thought I would point out the offers going. They are clearing out all of their stuff - go on their website to check out the unicycles and unicycle spares available. Ebay UK has some of their stuff as well.
Shame to see them shut down, I would have liked to have done work experience there.
Anyway, you might be able to find some good deals there . . .