^What he said. Replacing a dishwasher pump is not very difficult at all, assuming you can get at it. I replaced mine in 2011; cost me about $120 in parts, about ten minutes of online research and about ten minutes with a screwdriver, which beats buying a completely new dishwasher.
EDIT: Figure out what particular model you have (it should be printed on a sticker on the door or on the body of the machine somewhere around the door) and look up the instructions for replacing the pump/motor online. If you can find these instructions, remove the old pump/motor and try giving it a turn. If it's obviously broken (e.g. mine was seized) then go buy a new pump/motor. I bought mine at Reliable Parts off 61st Ave & 2nd St SE, in Phillips Park business park; a few blocks east of Chinook Centre.
http://www.reliableparts.ca/
You will have replaced the most expensive, complicated part in the entire machine for a fraction of the cost of an entirely new dishwasher. Mine worked like new, and still does to this day.