Same here Class A mechanic, 9000hrs for apprenticeship,3 yrs school, crap pay for way too long....Went to heavy equipment for 3 more years then got out, I tinker at home and thats it..
495.00 seems fair to me, and I think it would take me more than 4hours...........
Does that carb have a gasket? Is the guy going to rebuild carb with kit? or just clean it up?
One more thing, just think if you broke a bolt by tring to save some money doing it yourself, sometimes its just better to send it in to a pro and get R done. altho there is alot of guys doing it on the side for less $, however good luck getting your money back if it doesn't work in properly in 2 mths from now.
Good luck