I bought a Conceptronic CH3SNAS. This is the exact clone of a D-Link DNS-323. It has a 500mhz proc, and has 64mb ram. Currently, it is fast enough for my needs.
Stock, it has mt-daapd 0.2.4 (the stable one).
I put a debian etch base install on it, in which it chroots and boots SSH, FTP and latest Firefly nightly.
Price? For me, it was ~117 euro’s. (I bought it at my work. :))
Normally, it’s about 145 euro’s.