We are looking to move our laundry room and powder room to our back hallway, which is on a concrete slab. Currently the washer/dryer are in between the kitchen and living room (very noisy and inconvenient) and the powder room is right off the living room making for little privacy. The only thing in the back hallway is the water heater. How much are we looking at dollar wise to move the plumbing for the laundry room and powder room to the back hall?

You're asking us to make a estimate on a remodel that we haven't seen, don't know the labor costs in your area and have no idea how much material will be used.
We're good but not that good. Get three estimates from local plumbers and go with the one you're most comfortable with.
Good luck, Tom

Just did the EXACT thing your wanting to do. $2000 This inclued ENTIRE new drain from house to city, roughly 70 feet. Added laundry room on to garage (had same setup as you). Laundry tub, washer, and floor drain. Pulled permit myself, copper, pvc, and cement etc.