Self-host vs API
Open weights only save money past a certain volume. Below it, an API is cheaper and far less hassle. Enter your workload to find the break-even point between paying per token and renting a GPU to serve an open model yourself.
Workload
The two options
Estimate only, and self-hosting carries real engineering and ops cost this does not price in. GPU rental links are referral links.
When owning the model wins
Self-hosting wins on three things an API cannot give you: cost at high volume, control over a model that cannot be deprecated or repriced, and data that never leaves your environment. The catch is utilization. A rented GPU bills whether it is busy or idle, so the math only works once you are feeding it steadily. Use the VRAM calculator to see what hardware an open model like GLM-5.2 needs, and the comparison table to pick one you can actually own.