1) people who come, pick out the eyes, underpay you and you still have to destroy the rest via the dump.
2) people who come, underpay you and take the lot to pick out the eyes.
3) charities who come, don't pay you anything, and you lose the problem.
4) shops who will, grudgingly, underpay you if you pick out what you think are the eyes, and bring them in.
5) customers who will whine at you directly on Amazon, Ebay, or Gumtree or Craigslist, if you sell direct, at what you think is a fair price, completely under costing your own time, effort, postage, unpaid, hijacked and lost sells. PS your tax status on this is moot. But, you can incur costs which exceed your profit. Plus, when do you pull the plug?
I've done, or had done to me, all of these. (partner ran a s/h bookshop in the early 90s, we had thousands of books before we downsized, we donated to flood victims and ultimately lifeline who do an annual university sale, but we kept back a box of 1st editions of some things for future risk-sell)
Tech books are almost universally worth less than you wish. They age out rapidly except for a very very very small cohort. If you can scan ISBN barcodes and write python you can probably find these from some simple scripting. Or, pay some intermediary who has written this as a product, and will become rich on $$$ from you, while you find the books are worth less than the $$$ you paid for the software.
There are some that I really enjoy and I keep them. But they are very much the minority. Outdated stuff goes to the trash, because when it comes to collectables, most technical books are not and never will be. The ones that are, really are.
I still have original QNX manuals because although I'll probably never use a QNX system in a technical manner ever again, there are things in those manuals that are pure gold. Ironically, some of the material is considered modern because of SBCs and whatnot. Like Photon, which under a different umbrella, entails a fairly common feature set these days. So I keep them.
A bunch of 15 year old PERL books? Trash. Not the PERL 5 stuff, but that's because I'm not the least bit interested in PERL 6, so there's no update of the bookshelves there. But I definitely haven't kept the pre-Perl 5 books. Why would I? Same with all the old Linux Administrator's Guides et al, because nothing they recommend and focus on even exists in that format anymore.
You have a truck load full of books so bite the bullet and hire someone to take them away.
A receipt from the library - this is standard practice from the organizaiton when they get a donation
>I also think the donation deduction is valid if you waive the standard deduction so you'd have to donate $12K+ in order to get a tax savings
Donating a hundred books (even at a "face value" of $50) isn't going to get you over the threshold, but combined with other donations during the year, it may (or may not) be helpful