That's why I said "and someone to manage them". The difference is in the tens of thousands of dollars per instance. The savings from even a dozen instances is enough to pay for someone to manage them full time, and that's just for the first year. Year 2 and 3 you're saving six figures per instance so you'd be able to afford one person per machine to hand massage them like some fancy kobe beef.
A100 TDP is 400W so assuming 4kW for the whole machine, that's a little more than $5k/year at $0.15/kWh. Again, the difference is in the tens of thousands per instance. Even at 50% utilization over three years, if you need more than a dozen machines it's much cheaper to buy them outright, especially on credit.