there was fine print that allows the contractor to change prices, that doesn't mean they don't have an obligation to communicate that change in prices.

Any fine print just means the contractor has the right to refuse to do the work at the original price if prices and circumstances change. That is totally fair and reasonable. But fine print does not allow a contractor to have full access to a customer's wallet, giving them carte blanche to do work at whatever price they choose, and to still expect to get paid.

If there are lessons to be learned here, it's just as much on the contractor side as the customer side.