I believe most of cryptocurrency projects survive on donations. Unless OP is going to make a commercial project which has a good potential, he can just use free API...
What cryptocurrency projects are you talking about that survive from donations? What projects earns more than $20-30 per month from the donators
despite masterpieces like Electrum?
You can use other good free api as well. Personally, I have used in my website mempool.space, sochain, blockchair.com, and others over the last year. Recently, I have been using only mempool.space, bitcoiner.live and Coindesk API and never had any problems. I have about 45k visitors per month, which is more than 1500 requests per day on those API (as sometimes I make about 1 request per minute or 30secs depending on the page).
Thanks for the recommendations. I'm thinking to start a website that will need API, but I generally love doing things back endly (like setting up my own node etc). For testing, these sites are your best choice, though. As for the 45k visitors per month, is it the bitcoindata.science? Quite nice site, it totally deserves it.