Unfortunately the eBay alerts for new items will be the death of you if it's a sole point of getting one of these things, or anything of this rarity and vintage. It's mostly a waiting game. I'm still on my only one from 2017, and the units that came after on eBay have been out of my budget.
You could look at recycling centers in your area since cable headends tend to follow that policy, but I wouldn't expect units to end up there the moment you get into one, it would be a major pain in the ass to check every now and then for one thing. Patience is key.
You're more lucky to find analog STARs like the Weather Star Jr or 4000, keep your eye out for one.