The person offered me $8000 for five or $2000 for one.
Where did he say he was located? he is most likely trying to scam you, these prices are way too low, the lowest this gear went to was about 3k when btc fell to 31k before the difficulty adjustment ( which was the cheapest time to buy a mining gear for weeks), today, it's priced at about 3.3-3.5k, these are China prices which are in theory are the cheapest.
When someone offers you a 3k gear for 1.8k you should be extra careful, there are a few legit sellers in this forum such as grace, Scott, and kaboomrack, even if you don't buy from those guys at least check their prices against the other buyers if the price is way too cheap - you should probably avoid it, there are probably 10 scammers for every single legit mining gear seller, keep that in mind.