There’s a multi-account discount where, if you register all the accounts to the same email, then the first (main) account to sub pays full price, and the others get a 25% discount on some subscriptions (eg. 1 month and 3 month, something like that).
Depending how long you plan to sub for, the longer term ones offer bigger discounts.
The current most cost-effective way to sub, is to buy a large Plex pack when Plex is on sale, then hold on to that Plex until there is a Plex discount on subs in the NES store. Then you sub with the Plex. If you buy a large Plex pack on one account, you can transfer Plex from it to the other accounts.
For catching up on things in general, you can check some of the replies in this thread: