10 petabytes at AWS is $210,000 per month just for storage (even excluding AWS's very high egress and transaction pricing), so even $1M (which seems like a high estimate indeed) would be amortized in less than six months.

Also, the hardware can be depreciated, which reduces its net (of taxes) cost dramatically over time.

Five years (probably the useful life of the equipment in general) of $210,000 per month is $12.6M. That's a lot of savings.