It is not the OCR that is costly. It is the JavaScript execution to render the page so you can do the OCR. You can even increase the JavaScript execution cost if suspicious.

You will also have to automate all page variations and the traditional challenges (login, captcha, user behavior fingerprinting, ...)

At the end the development time, cost and server cost will kick you out of business if you are too dependent on the information or you start to loose money every time you scrap.