Presently is 400$ per gtx1660 Ti a good buy? Now that no one knows how long mining profitability will keep up, is this a good price to buy or I should let go and wait for later? The offer consist of just three of this graphic cards right now, what do you say?
The price is definitely cheaper than in my country (about $500 right now for 1660 Ti). With 1660 ti you can get about 30 Mh/s for each card which can earn you $4/day right now and with that you can hit BEP at about 3-4 months and if you need to buy other part for the mining rig then you'll need more time to break even. Keep in mind that the income right now is very high (it used to be sub $1/day last year and about $2/day early this year) and can decrease as the network difficulty keep increasing, the activity of ethereum network, the talk about EIP 1559, etc. At the end of the day it's your decision whether you are comfortable or not with this kind of risk. You can probably sell the card for $100 if the market crash later and a lot of card flooded the market.
I think that 30 megaash in mining with 1660 ti is a very good result. In most cases, I saw 27-28 megahash, but of course it all depends on the memory of the video card.
Before the mass purchase of video cards by miners, the price of this video card was $ 220-240.
$ 400 is a very good price because these cards are not on sale right now. But don't buy graphics cards with a single cooler.