Today I picked up an ASRock E350M1 from a local computer store for 94 EUR. I'll never be able to use an Atom again!
On this mobo, there is an AMD E-350 Dual-Core CPU with a Radeon 6310 (comparable to 5450) graphics core. To use this board with open source drivers, you need xf86-video-ati-6.14.0 and kernel 2.6.38_rc1 or later. The proprietary driver supports it too, but I didn't test that.
According to various reviews, the E-350 does fairly well against the competition. Let's see how long compiling LibreOffice will take.