Every Thursday around lunch, I open up Estatesales.net and browse the sales for the upcoming weekend. There's typically a dozen or two. I open each one in a new tab, and scroll down through what's typically 100-300 photos per sale. Very quick skim, stopping if I see anything interesting.
I then paste links to specific photos into item-specific category threads in a local makerspace chat: Sewing machines/other fabric stuff, Typewriters/addingmachines/cashregisters/calculators, CRT TVs/VCRs/related, Computers/videogames/peripherals, Tools, Cameras/film/telescopes/projectors/optics, Radio/stereo/DJ/vinyl records, Landline phones. So basically I've done the horizontal browse and sorted it into vertical categories, and anyone who follows those threads for stuff they're interested in, can go to the sale and nab the stuff.
But crucially, estate sales have _everything_, and if the sale folks have reorganized the house, badger them into telling you where the accessories went. If they already threw out valuable cables or something, give 'em hell for it and refuse the purchase, and they'll be more mindful next time.
If you're looking for something specific, show up on the first day. But personally, I just want to keep it from being landfilled, so I show up near the end of the last day. Offer fifty bucks for all the VHS tapes in the house, they'll take it. I got about 3500 floppy disks this way -- other shoppers ended up helping bucket-brigade them to my car as the clerk was closing up shop.
There will be people, the executors of the will, that need to clear the house, however, much which is just $$$ to you will be heirloom grade stuff to them, with memories of happier times attached. Yet still, they need to realise the assets from the estate, maybe there are grandchildren with inheritances in that mountain of cruft left over after a long life.
Sure, there are things that just need to go, that the executors of the will would consider paying to get cleared.
As for getting things like the cables and power bricks that go with electrical items, chances are that the deceased was not doing a good job of keeping everything in order, they might even have a bit of hoarding going on. It is no easy job to repatriate cables with electrical items, that might have gone to the tip already, as e-waste.
There is also a tendency for men to put value on what most women will just see as e-waste. Similarly, with clothes, men see the whole lot as jumble sale trash, whereas women are more likely to see value in these items. I say this not to court sexist allegations, it is just that, if a woman clears the house, there is a slimmer likelihood of getting that lead for that obsolete electronic kit that somehow is considered valuable.
Sometimes the estate is too much work for the relatives, so the solicitor might get the keys to the house and instructions to get it all cleared. These are a minority of cases, usually, the relatives do pick through everything and put stuff in charity shops, charity shops that deal with big items of furniture, up to half a dozen 'skips' (British English term) and so on. I would say there isn't going to be a estate sale in these situations, really you are relying on the minority of sales where the solicitor gets the key, if you are going the estate sales route.
Which means they should know better. And some of them do -- I have a few local favorite companies, where I know they'll keep things together, they're good about finding manuals in file cabinets and putting them with their respective items, etc. I'm usually happy to pay their asking price, because they're interested in seeing the items go to good homes and get reused, and take care accordingly.
But, likewise I have some "un-favorites", one who was notorious for sticking price-tags on screens. I might've finally trained them out of this when I told them I'd only pay their asking price for a particular piece of test equipment if they could remove the sticker without damage. They removed it, the already-degrading plastic screen was obviously fucked by the adhesive, they exchanged awkward glances with each other, and I walked away. Maybe they'll keep that in mind on the next sale they run.
As exemplified by what is going on in the Middle East, the USA has different values to the rest of the world, so don't take this criticism as a slight, just don't come here and expect to be liked for what you are doing.
Some of the more rural thrift stores still have VHS, one still has cassettes, and I know of a place where there's a stash of 8-track.
Thrift stores are businesses; they stock what sells - but they also have the reality of often having to pay to dispose of electronic waste that was donated - they're not allowed to just dumpster it as in days of yore.
Of course the national thrift store chain machines (Goodwill) have policies for all this stuff - you gotta hit up and get to know the smaller independent stores if you want them to hold stuff for you - which they'll often do.
A VCR and some tapes are great for the kid's playroom - teach them rewind patience on equipment you won't cry much if they destroy.