there is (or there was?) an archive of pdfs online, and there were tens of thousands in circulation so you might struggle to generate interest on ebay (but you never know).
I think mixmag went downhill after 2000 - maybe that's when Viv Craske edited it (pick up a random copy from that era and count how many times the word 'bosh' or 'mongo' appears!) but the website has some interesting stuff these days. They obv struggled to keep up with RA, Ransom Note & co though. BITD, It was fun leafing through the record reviews in Smiths whilst you were waiting for a train - does anyone still do that?
*whilst on this, long shot but if anyone has any old copies of 'Jockey Slut' or 'Shoreditch Twat' from around the same era, I'd love to re-read them.