I think starting HDD mining a few years back to mine BURST was the worst mining decision, ever. Even worse than buying some obsolete ASICs.
Basically I would go on eBay/Craigslist/etc and buy the best deals on HDD. Bought tons and tons of these drives and by the time I was ready the profits started to plummet. No big deal I assumed? I assumed just like GPUs and ASICs I can just sell it back and get back maybe 50%-75% of my money, no not the case.
You don't realise it but almost nobody buys regular HDD second hand. Still got a bunch of them laying around. These days you can buy a 128GB flash drive for like $10-20 so why would you buy some old HDD for around the same price? Still got a bunch of them laying around. Maybe will take them apart and use the strong rare earth magnets to hang stuff on my fridge.
I already said about my bad choice of mining with HDDs, but I forgot this super important fact about the used HHDs or SSDs, nobody buys used stuff to data storage, it's "cheap" to buy new hardware and safer.
The reselling factor of HDDs is almost zero at least in my country, or people offers like 50% of what are you asking.
GPUs was/is easy to resell, never had any trouble to find a buyer, but I have some HDDs here.
My solution is to use them to work, sell to my friends whem they are going to buy a PC, and use them to keep my data. At least I have HDDs and SSDs for at least 5 years
But HDD mining was my worst decision when comes to mining, even CPU mining was better than HDD because I can sell CPU easily too, like GPUs.