While I would like to say never less than $30 to mow any lawn, I hope people who mow lawns take into consideration who they are mowing for. Is it the strong young guy next door that could do it himself but doesnt mind helping you out? Or the little old lady who can't do it herself, lives alone, and on a fixed income? I think $30 is a fair rate for a small yard, front and back. I'd mow the old lady's for free. What goes around comes around.