if they are so tight your gonna get cut then i dont think it matters if you are charging 9 - 10 quid , stick your quids on and that will offset the lost work always
If you lost a grands worth id say you were unlucky
I bought a round with big houses
Lost nearly £150 over only 3- 4 jobs , 2 moved 1 undercutter 1 lost
It happens but you pick em up again