Pretty good deal at www.woot.com...4gb clip+ for 19.95 + 5 dollars shipping, get as many as 3.
And yes you can rockbox them -- the latest build has been very stable for me, getting over 17 hours of battery life now.
It's things like this that make me hate living in Australia. I would have jumped on this sale like there is no tomorrow.
I can't even buy things on Amazon let alone get specials like this from woot and all those other types of websites :/