Yeah, in essence it helps start ups integrate stripe without building their own backend

Startups would put in their restricted key - a secret key with only the access that is necessary.

In terms of pricing, a request is an api call. I can see your point with $5 to send 250 text messages. It does sound steep. The first 5000 requests are at $20 which should adequate for most startups. Majority of our customers don't use more than 750 right now.

If we find customers maxing out the limits too quickly we will definitely adjust our pricing