> How much would it cost to be be done by a professional?
Parts alone are about $120, say 1-2 hours labour plus trip charge -
looking at $200-250. You have a stack unit, so may require additional time.
I'm no longer in the business, one of the other appliance guys on here
should be able to give you a better indication. Obviously, you have to
decide whether to invest that kind of cash in a 7-8 year old appliance.