There isn’t much price competition so your only choice to save money is to switch back and forth between the promotional offers and switch when the promotion ends. Both cable and landline CO’s know this, that’s why they only started to offer the discounted internet service if you bundle with TV service. And if you don’t bundle, sometimes they will data cap you each month to discourage you from using another streaming media/tv service (that was the point of net neutrality where an ISP couldn’t force you buy content from them by making the cost to obtain content more expensive elsewhere).
Anyway, that’s why I mentioned Tmobile’s 5G service as a 3rd option because it’s really the first time in a long time we have a viable alternative that is priced competively. TMobile 5G isn’t really the 5G we are looking for, but it’s a step in the right direction. And the service should get even better once it completely the acquisition of Sprint. Unless you are a power user, TMobile might be a viable option for you. And if you already are a TMobile customer, you might be able to convince them to give you a bundled price.
There’s actually a 4th option but it’s neither cost effective nor is bandwidth great. It’s ISP via ViaSat, but the sattelite link is only good if you live in some rural area, trailer park, or boat, which neither cable, phone, or Tmobile 5G provides service… Or if you insist on having internet access anywhere because you are preparing for the end of the world, as some piggs appear to be.