Do you have to pay for a router?

Excuse me, could you please clarify something for me? I'm a bit confused about routers and whether or not they require payment. Is it a necessity to pay for a router, or are there instances where one can obtain a router without any cost? I'm trying to set up my home network and want to make sure I have all the necessary equipment, but I'm also mindful of my budget. Could you shed some light on this matter for me?