how much is the paid version? is it worth it?

https://support.chess.com/article/1363-what-does-each-level-of-membership-get-me
This article may help you

Yes worth it. Probably the most entertainment value for my money. The amount of time I am on the site divided by what I pay, is next to nothing.
As for is a paid membership worth it- I say you’ll get out of it what you put into it and I’m not really talking about the money paid but the time and use you do with that paid membership. There’s a lot of knowledge you be gained and accessed with a paid membership here it seems, but you have to take the time to review and apply it to your game to reap the benefits.

The paid membership is worth every penny. I've got platinum because the only thing diamond gives me is lots of videos, and YouTube is full of chess videos. But the puzzles, drills, computer opponents, etc. etc. are more than worth less than 20 cents a day.
And remember, chess.com is the premier chess website by far! And they're always improving old features and continuously adding new features. They don't do that for free. If every member of this site played on it for free instead of paying something, it would soon cease to exist. The only reason free members get to have access to it is that the rest of us fork over a little cash.

It all depends who you talk to. You can bounce around to get freebies but personally I like to keep everything under one roof because between my mobile iPhone and app, I accomplish everything desired on very little cell data usage which itself is gold where I am located.
If you play chess from your lap top, then you can bounce around on analyzing tools and puzzles. I play against the engine a lot is it’s convenient to use the analyzer. I do the 25 puzzles per day which is more than plenty.
The “Explorer” is a valuable tool for statistical purposes and analyzing master games and tours too. I use it for citing ideas in the middle game planning and winning lines.