GE JVM1740, stainless steel 1.7 cu.ft. 1000w 300CFM, pretty generic spec except a real metal / stainless steel handle (looks nice), manufactured in 2008 and installed in 2009 I think.
The ventilation motor is getting pretty noisy (worn bearing, but still works) after about 8 years of use. Replacement motor-fan is $150-180 new. I can find a used one on ebay for about $20-50 but being used I'd expect it to only last about 1/2 as long. If it can work for another 5 years I'd say I got my money back.
A replacement stainless over the hood range of similar spec would cost about $180-300. Ideally I would like to have stainless (not black stainless) again so it matches the rest of the kitchen, if I absolutely have to I can go black (but prefer to pay a little more instead). I really dislike those grey plastic handle on many stainless microwave because it makes it look much worse. If I buy, I'll be doing the install and hopefully the holes line up so I can install it easily. Last time I had to drill new holes when up grading microwave and returned an LG because the holes are outside the 12" deep cabinets above. I don't know what were they thinking when they make that spec.
What would you do it if you were me?