I have only bought my miners direct from manufacturers when it comes to ASICs. I dont like buying them secondhand without any type of warranty. Especially if you are buying in this bull run or over the last 12 months or so you are already paying a very large premium just to buy the machine and if you buy it second hand and something goes wrong on day 1 you have a very expensive paperweight if you don't know how to fix it yourself. I would recommend waiting for prices to come down or being prepared to have a longer break even time period if you want to have a little more peace of mind if something breaks you at least have a warranty to fall back on.