Girls and Boys !
Your calculations does not take into account that thing that UNTIL the whole markets are banned you are earning 10x in every month with ASICS so it really does not matter do you get 50% back (or even a bit more) from your initial investment when the game ends.
ASIC miner just throws the worthless ASICs to a trashbin and walk away 9x richer than GPUs owners...
Problem is: nobody sells to you a money making machine at a good price
Nobody is making 10x with ASIC except from PR users paid in machines delivered on time, to do promotion
GPU is still here for a reason

Im not saying GPU is dead. But the fact is you will get much better profits by ASICs. My message and point wasn't the exact numbers but the profit gap. It is large enough so the resale value does not matter in practice.