People put FREE STUFF on Craigslist all the time, so you might get lucky there, but I'd say the vast majority of people would just throw them out rather than take the time to list them for free.
About 10 years ago I threw out a BIG stack of MBA issues - damn near every issue from about 1988 thru 1997 (I had a subscription) because I thought I'd never look at them ever again. :shock: :roll: My reasoning: the technology is always improving, so who cares about all this old stuff.
I'm still kicking myself to this day.
I emailed MBA a few months back, and they said they have a bunch of back issues, but there's no financial incentive for them to scan them for posterity.
How much money does the seller want for them? I have a scanner and wouldn't mind scanning an issue or two for the common cause. Anyone else? If everyone pitched in we could immortalize a substantial part of MTB history. I see the OP is new here, but perhaps a RB veteran wouldn't mind taking this on (buying the mags, accepting contributions, and assigning issues to contributors to scan and upload). I wonder if server space would be an issue?
Just a thought. Standing by with my scanner at the ready...