I ran into the same issue…
My very little hobby extension “Top Clip” reached such an incredible high (and totally unforeseen) adoption rate, that my light REST API (3 endpoints) is actually called ~500k times a day…
My suggestion: Go with free credit from a cloud provider. During the free credit duration, build your monetized extension (the more value it offers to streamers & viewers, the more revenue it will create!). Release the extension. In a perfect world you’d still run on the cloud provider’s free credit while the first revenue of your monetized extension arrives 