The author of the content can be tipped, because he can access the address used for posting. Also, content can be encrypted and decryption, after payment, can be automated.

Thanks, makes sense now!

The Bitcoin blockchain stores and secures a ledger. So these websites are just content (text, code) encoded and published through various entries (outputs) on that ledger. You can publish on the Bitcoin ledger for 1 satoshi/byte and an average transaction is around 250 satoshis. These include info on the "sender", "recipient", amount, etc. But with the a special type of opcode you can also publish strings. So the cost of publishing on the Bitcoin blockchain depends on the size of the text you need to publish.

A satoshi = 0,00000001 bitcoin and 1 bitcoin recently crossed 10k dollars. So being conservative, 10 bucks would allow you to publish a very simple website.

Bitcoin's blockchain is a terribly inefficient place to publish websites, unless you're looking for censorship resistance. The Bitcoin blockchain is secured by the strongest network on the planet by far. So once you publish it you can be pretty sure it won't be easily taken down.

Navigating the blockchain in the sense I think you mean wouldn't cost anything. You'd just need to interpret the encoding of the text that was published.