a few days ago I tried to find out about how botnets work through captcha solver
I think it's almost impossible for them to make a profit from free rolls if they can't use the lottery they get from free rolls, unless they get a special discount.
because the cheapest price that I found showed almost the same price as the free rolls game provided (1 USD per 500 captcha)
but I don't know if there is a captcha solver that offers a cheaper price
There is one provider that gives a 50% discount on that price if the solve matches our domain name. Those are just retail prices and bulk discounts are available. I also know someone that has his own captcha solving server which is free (other than hosting costs). I'm sure many others do as well. It is real problem that there isn't an effective captcha on the market and Google don't address the design flaws in theirs.