Hmm, tempting, but it seems clearly intended for use by scrapers? Even the bottom $4.99/mo tier is for "2,000 solves a day"[1] which is slightly more than the 5-10 I'd say I run into on a bad day as a human... Something like $1/mo for 50/day would seem like it was really meant for legit use.
1: https://nopecha.com/pricing