Well, if you only ever needed a $20 subscription's worth of tokens it would never make any sense to buy hardware since even at 2018 prices you could buy 20 years of subscriptions.
Assuming $20 subscriptions continue to be available for 20 years. Maybe they will, I don't have a time machine, but $20 subscriptions seem to be the $1 Uber ride level of pricing.
Sure, I'm just saying, even for "mundane" computing tasks where the hardware is cheap, if you're optimizing for cost, renting hardware is always the better choice.
