Dang - that would have been a hell of a haul. What's sad is that somewhere out there, in small town garage sales across America (and elsewhere), are lots of old game magazines just like this that some parent has set out to the curb with a free sign thinking they are not of value anymore. It would be a fun project - if I had the time and resources - to set out and hit up as many garage sales as possible and see if it's possible to score any vintage game magazines. It would be neat to make a thread on this site just for that, and anyone with garage sale finds could post their hauls there. In my experience with garage sales, it's pretty unlikely to just randomly chance across vintage game magazines. I think it wouldn't be a bad idea to chat with the host of the garage sale to see if they have any old game magazines laying around. Many people who run garage sales are empty nesters trying to get rid of their kids stuff, and you never know if Jonny had a pile of mags in his closet and maybe they didn't think those would be worth selling but would be happy to get rid of them.
As an aside, a few years ago I came across a yard sale that had a huge box of old car magazines in pristine condition (I think it was Road and Track) from the 90s. It was all free, and being a sucker for old magazines I took the lot. I can't imagine there are comparable sites for old car magazines, but you never know. If there were I'd donate them