The Panasonic WJ-AVE5 is a fun entry mixer for analog needs. I've got a couple of those and also a Videonics MX-1 (also good for feedback), all bought from eBay at least a decade ago. I've not looked into how much they're going for these days but whilst sorting through old video equipment for a public screening of some VHS tapes I organised a couple of months ago, I looked at what the value of my Datavideo TBC-100 was and was floored to see one had sold on eBay for £1000+! I thought paying even £100 for it was a bit steep at the time.