Another Question / 1999 Rotors

I had a real bad bumping in the front of my truck when braking. Had new brake shoes and pads put on and the front rotors turned. Fixed that problem, but they showed me where the back rotor are almost done in and they couldn't turn them or when water hit them they would warp. Well, now when I brake I feel that same bumping up and down in the rear. My question is: I can't afford new rotor for the back....what damage could be done by continuing to drive on the ones I have?

Bump!

you will eat your pads up. no real damage, just an annoyance