Depending on where you live, and how professionally you want the job to look like, here are a few suggestions.
Professional painters generally charge by the room. $100 to $150 per room, and the package deal is $300 to $500 per house, but that's variable to room size.
You may be able to get a quality job done by foregoing an actual painter, and contracting a local maintenance person. They do a pretty good job in their own right, but will charge between $12 and $25 dollars an hour.
You can take a chance with quality, and put an ad in the local paper or on Craigs list, and flatly state that you'll pay 10 bucks and hour for painting. I am fairly sure that you will get many responses, and it could be a very good deal for you.
OR, get some friends together, make some chili or BBQ, and have a painting party! That may be the best way to go!
DALE Y THE MAINTENANCE GUY