Leak between the housing and the motor; spr...

Dishwasher fills with water and motor runs, but no water is being pumped during the wash cycle. The water doesn't pump out/drain our of the dishwasher during drain cycle.
Question: Is the problem solely the pump, or are other parts involved in the problem? Is this a problem that I could fix (i.e. if the pump is broken, could a novice easily disassemble and reassemble all the parts)? And, if not, how much would it most likely cost? Finally, given the age of the machine, would it be more cost effective to buy a new dishwasher?
Thanks for the help.
Chris