How much should i pay to have someone come over and hook up a 5.1 system to a plasma and a ps3, DVR, and a wii. they would only have to pull wire for the rears under the floor. I would have they installer calibrate everything as well.
It all depends on the layout of the room and how "easy" it is to get wire from one place to the other.
Typically with my company we would charge $700-$800 and include all speaker wire, interconnects, wall plates, mount (if flat on wall), and remote programming for something like that if it didn't invlove anything dramatic like removing trim or carpet, etc.
*NOTE: Labor rates can vary depending on which part of the country you're in as well. Quality of work, work experience, etc. all add up as well. Some guys will work for what amounts to lunch for the week, but that doesn't mean they're good at their job. If someone's really cheap, it's usually for a reason.