I just bought a Fender M-80 160watt bass amp (late 80's - early 90's) for 180$, and I was wondering if I got a decent deal.

I like extremely low frequencies (I usually cut the mids and highs), and I bought this to match with a Marshall MG-Series 100W Stereo Combo
man, no wonder no one answered this. their bowels probably turned to water at the sight of those amps.

if he swindled you, then know that it was only for a few bucks, you'd have probably payed around 300 for something like it new. that being said, you may have been able to find it around the 120 range, but i doubt it. so if you're happy with, it is a good deal. and in general i would feel like i got a fair/good deal out of it, if not a great deal.
punk isn't dead, it's always smelled that way.

"A perfection of means, and confusion of aims, seems to be our main problem."