Tā shuō wénzizàixiǎoyěshìròu, jiǎn dào yīkuài qián yě kāixīn.
He says even a mosquito is meat - he's happy even picking up one yuan.
Tips
usage
A 俗语 (suyu, common saying) rather than a classical chengyu - colloquial in tone, used to justify accepting small gains. Often shortened to 蚊子腿也是肉 (wenzi tui ye shi rou, 'a mosquito's leg is still meat too').
memory
Picture wringing 'meat' from a mosquito - absurd, but the point is that nothing is too small to count.