I have a contract for deed. No late payments and was filed over 2 years ago in ILLINOIS. The guy that owns the property called today saying he is going to sell all his land to a different guy and I will be making my payments to him and that the payment will double and I will be paying for the same amount of years. Which will make me pay mor than 12k more than what we signed the contract for deed. Can he do this

... can he do this

Probably not. If and when the current owner sells, and the buyer demands the increased payments, check with an attorney in your jurisdiction.