What the cost would be for someone to make the necessary plumbing changes in Laundry?

Currently I have a laundry sink in between where I would put a washer and dryer (havent purchased these yet so there's space to work).

I want to switch between where the sink and washer is, so rather than the current layout (dryer - sink - washer) i'll have it: dryer - washer - sink.

How much would it cost to change the plumbing for this? Assuming this means:

a) moving the existing drain and hot/cold supply lines (previously for the washing machine) down for use for the new laundry vanity/sink, and;

b) moving the existing drain and hot/cold supply lines (previously for the laundry sink) up at least 30" from the floor for use for the new washing machine.

I can repair the drywall myself, just want to find out what the cost would be for someone to make the necessary plumbing changes.