"Netscape Navigator was not free to the general public until January 1998" - wikipedia
As others have mentioned, Netscape Navigator was free to individual users. Corporations using it were supposed to have site licenses, but in my experience this was mostly ignored en masse. I certainly worked at a couple of companies in that timeframe where everyone used Navigator at work but the company didn't have a corporate license and the situation was constantly joked about, the way people joke about WinZIP/WinRAR nag screens saying you are on day 1099 of your 30 day trial or whatever.
The archive.org provides the answer. For not even $50, Netscape Navigator is yours!
No, you're not crazy. Netscape Navigator was not free as such, but if I recall correctly, was free for individual users, schools, non-commercial entities, etc. (Am I mis-remembering this? The Wikipedia page doesn't have much detail.)
No, you're not crazy. It certainly became free. I just remember that there was a period when people were forking over actual money for a browser that wasn't IE.