I would not buy now with new nvidia gpus comming and all the asic popping up.
I completely agree with this guy. Not advisable to buy GPUs this late. There is the threat of ASICs (for Ethereum and other algos/coins), the upcoming ETH switch to POS (end of mining), and more. Basically the risks are stacked against you at this point.
Unless you already have the hardware, it may no longer be wise to start mining today.