Premium Economy, is there a trick to it? (Flying from Scotland)

So, the dates we were looking at for our trip are now available (FEB/MAR '27), and we're hoping to fly premium economy... The route we'd be flying is EDI > HND via FRA. So, this route is run by Lufthansa (and sometimes jointly with ANA)

From anyone's experience, what sort of price should be considered 'good' for PE? I think at the moment it's £3300...

Are there any alternatives you'd suggest?

When should PE be booked? This whole trip is for my 40th, so getting PE would be rather nice (it's as far as I can stretch budget-wise, unfortunately - no Business class for me) If you all have experiances that say it doesn't really warrent the extra ££ we'd be find flying Economy too; i'm just weird with sitting next to a strainger for 14+ hours (anxiety) This is where the 2 3 2 seat layout would be handy.

Sorry, that was a ramble and a half!