Level 1
In terms of functionality, the difference between free and paid versions is not all that great - you can attach files (which is somewhat cumbersome, as opposed to other PW managers), and the tools for checking passwords etc. are not all that earthshaking.

That said, for only $10 a year - less than a dollar a month! - and to support what is unquestionably a very worthy project I think that the upgrade is money well spent. Indeed, I am very happy that I upgraded, even though I have lifetime subscriptions to Sticky Password and Enpass.