[fweimer]

Google still offers free Usenet access, but alas not over NNTP (I think).

These days, with reasonably cheap virtual servers and reduced Usenet traffic, you can just run your own server after finding one or two peers to exchange articles with. The Debian packaging of INN is quite good, I think. It's still a bit of work to set up things, but so is reading and writing articles.

All of this applies to the text-only Usenet. A lot of for-pay Usenet was actually about access to binary-only groups with content of questionable copyright status (or even legality, depending on country). I don't know if that's still a thing today. The bandwidth requirements for these binary-only groups could be significant.