The goal isn't to pay minimal money. If that was the goal, you strap an air filter to a box fan and use an esp32 to turn the power on and off. Or a solid state relay if you want to get fancy with different power levels.

The goal is to do harm to anti-consumer companies. Buying their (subsidized) hardware, and then breaking their lock-in so you and others aren't shown ads or forced to pay useless subscriptions, harms the company.