If you use the excess memory for AI only it's cheaper to rent . A single H100 costs less than $2 per hour. (incl power)
Not affiliated, just a (mostly) happy user, although don't trust the bandwidth numbers, lots of variance (not surprising though, it is a user-to-user marketplace).
I don't even know how these Vast servers make money because there is no way you can ever pay off your hardware from the pennies you're getting.
An alternative is to use serverless GPU or LLM providers which abstract some of this for you, albeit at a higher cost and slow starts when you first use your model for some time.
Not for the GPU poor, to be sure.