Internet Service Providers usually have a promotional price for first year to attract customers, and after that year the bill can go up significantly. If there are multiple ISPs available in your area, it is likely that the promotion price for each is similar.
One trick you can use to always pay the promotional rate, is when the first year expires, give them a call and tell them that if they raise the monthly bill, then you will cancel their services and switch ISP. In the 7 years I’ve been doing this, this has never failed, and I’ve never paid over the 1 year promotional price for internet. They will always rather keep you as a customer.