I have not seen many setups that wouldn’t pay itself back (including energy in my case) within a year (sometimes even 6 months) with buying vs renting. For something that pays itself back that fast, and that is without renting it out myself, just training with it, I cannot see how I would want to rent one.
Edit; on Lambda labs, the only exception seems to be the H100; it would be 1.5 years or so, but even 2 years would still fast enough. I have an A100 which paid itself back; thinking of getting another one.
I think the downside to buying hardware as well is that compared to other tech, this LLM/ML stuff is moving very quickly, people are great at quantising now (whereas I only really saw it done before for the coral edge TPUs etc).
Someone could buy an H100 to run the biggest and bestest stuff right now, but we could find that a model gets shrunk down to run on a consumer card within a year or two with equivalent performance.
I suppose it makes sense if someone wants to be on the bleeding edge all the time.
Edit; on Lambda labs, the only exception seems to be the H100; it would be 1.5 years or so, but even 2 years would still fast enough. I have an A100 which paid itself back; thinking of getting another one.