i doubt any farm would phase out 3.5PH+ all at once. in short, it's unlikely you would be able to pick up 1000 units all at same time, even from the same person.
Say it takes them 5 days to pull these rigs off, are you compensating the 5 days of revenue loss? If not, why would they stop all units at once?
I have brokered larger deals. Especially in this situation that if OP isn't just lying means that an entity with exceptionally low power cost is willing to pay a slight premium for equipment that is non-profitable to run in a power cost premium area.