Looking at eBay listings, lots of used Hackintoshes are offered, but very few are sold.
If OP wanted to successfully sell his computer, he would have to put Windows on it before offering it on eBay. And even then, I don’t think he’d get much more for it than the price of the Windows license.
On the other hand, had OP spent his $800 on a Mac mini, he would be able to sell it for close to retail price. Even after a year, he could easily resell that computer for $600.