For those who know, are the S19 Pro that can be found at reputable sellers on Alibaba the same as ordering on the Bitmain site?
Avoid Alibaba like the plague, you can find other trusted sellers on this forum, but do you really want to pay close to 14k for a miner? what about tax, how much do you have to pay to import a miner like that?
Do you think this information sounds realistic?
They don't, this is based on static difficulty and price which we all know is impossible, it all depends on your luck, let's assume difficulty is going to be same if bitcoin price goes to 150k the S19 pro at your power cost will make you about 3k a month, so for 14k investment, you would need a little under 6 months to ROI, if however, bitcoin price drops to 27k, your miner will make you $500 a month, and that will be over two years to ROI.
To put this in a simple and yet somehow accurate way, when you buy bitcoin mining gear you are essentially betting on the price to go up if you believe that will be case until you hit ROI, then go ahead, if not - don't. The point here is not to get your hopes so high, know that the difficulty is only going to go up and the price can't go up forever, if you understand the risk and the dark side of mining then mining is a great business, if you don't, you will end up losing money just the like the majority of people who invest in something they don't quite understand.