I had an iDrive account with over 10 Terabytes for one year. 1st year was less than 10 $ for testing, but when I accidentally came over quota for only some weeks they charged me more than 400 $. They say: “Quota overages are charged at the rate of USD 0.25 per GigaByte per month for as long as you are over quota.”
So please make sure to never overrun your quota! Or even better just don’t use services where scam is part of business-model.