That's a colossal number of tapes. The few I found that had been stored in boxes since the 80s had mould on them, hopefully the collection doesn't have mould.

Sadly, it's simple, you pay someone to come and dispose of it.

VHS tapes sell at easily more than $1 a pop. That's 50k dollars.

Good luck finding someone who will pay you $50K for cash and carry. The problem with a lot of old stuff is that it has value to someone. But finding that someone who will take it off your hands without much friction isn't easy.

Digitise, digitise, digitise!

To what end? Digitizing is a huge amount of work.

It’s collections like this that sometimes turn out to have the only surviving copy of the Apollo moon landing broadcast. I would digitize the report of what is in there and make it available on the Internet as fast as possible, so that people who are interested in this stuff can see if there’s anything that is not available elsewhere

Yeah, this is my likely approach - it’s not impossible he’s got some BBC stuff that’s otherwise lost, as he pretty much ran two VCRs continuously for a quarter of a century, from the early 80’s to early 10’s - but it’s mostly just hoarding.

If and when it’s a relevant problem for me I’ll go through his catalogue, digitise anything worthwhile, and then dispose of the lot, be it through sale as recordable media (they should all be in great shape, as he stores them well) or otherwise.

I recommend contacting the local retro computer or cinephile (or generic "geek') scene and see if you can recruit volunteers to digitize them for you. I would volunteer for this, take a crate home and pop in tapes while I go about my normal day.