I think it is too soon to tell if Plus is "worth" the price. I know you said you are in EU, so if you do not have LBP and are interested in the game, perhaps it is worth it to you. Being from the US, I picked up Plus day one because I think I will get more that $50 worth of playing experience in the first year. Plus the 3 "bonus" months means I am paying $3.33 for this rental service.
If the "right" games are discounted (i.e. some titles I actually want) then Plus will end up being a worthwhile expenditure for me.