you can get a vu33p on a mining board for 1949$, this was done by pushing xilinx to lower prices. You absolutely can get proven chips discounted at volume pricing.
Oh, I understand, you are talking about discounts.
But I do not understand why the difference between $ 9 and $ 1949 is not obvious to you ... This is the abyss.
In addition, do not forget that Xilinx makes its boards for the general needs of the industry, and not for the needs of cryptocurrencies. And in the case of your project, you can make them the ones that are needed in the cryptocurrency sphere. For example, with a large amount of RAM, with thicker data buses, with other frequency bands. For example, with microcells, you can put an oscillator on a chip, which will produce from 5 to 10 GHz clock frequency, and on Xilinx chips you will never overclock.
I suggest you to develop your own sports car and drive along roads where YOU want a speed of 300 km / h for a total of $ 10 for each trip.
But YOU tell me that for each trip you can buy a regular bus for $ 2000 (with a discount) ... which goes only along the planned route at a speed of 60 km / h.
Do you see what we are talking about different things?
Yes. But you're talking about a very serious, ultra-skilled startup that will burn millions in a blink. Not easy, not low risk. The expertise needed to stand any chance of success is considerable. Sure that experience exists, but even the best minds get tripped up by the speed of change in crypto, the market instability, etc, etc.