Have a look in the Yellow Pages..
Although on behalf of whoever gets to fix it, please give it a really thorough clean first
Although grill/ovens are more expensive, repair fees can make a new one look cheap.
With computer monitors I have been quoted £40-£50 just to look at them.
So I fix my own.
Whats actually wrong with the Microwave? total power failure, buttons don't work, not heating up, sparking, etc?