There are many APIs for obtaining Bitcoin prices, some paid, others free. A Bitcoin price API built with LSATs may issue a macaroon to each new user, allowing for some free usage. Upon hitting a daily or total limit, the API can issue an LSAT together with a Lightning invoice. There could be separate pricing for surge traffic or historic data. One idea is to issue LSATs that include a “delay” as a caveat. Free access requests are served after a few seconds, while paid access is served immediately.