I use IP.Board for my forum solution. Its renewal price has never gone up.
I no longer use WHMCS for web hosting, but for client management, billing, and software sales. However, when I used it for web hosting, the monthly costs my servers have never gone up.
Costs and fees go up all the time. But when you sell someone a product with a given renewal price, you don't jack up the renewal price. It's just not a thing that happens. Nobody sells web hosting and then just arbitrarily increases the monthly prices for existing clients. They change the price for new orders.