Each their own I guess, I myself found it a worthwhile 15 dollar payment since I only had to pay once (and the optional expansions) and I have a lot of fun playing. Plus 15 dollars is very cheap, I went to the movie theater the other day and around here it is 11 dollars a ticket! That was a major rip off I thought since I could have endless hours of entertainment with browser games or pay to play MMOs and I only get around 2 hours of entertainment at the movies.
And there isn't just "4" people playing, I usually see around 50-70 people playing at once, sometimes up to around 100 at peak time...which is pretty good for a browser game.
Most free to play browser games have nowhere near as many features as Lands of Hope does, even Runescape you had to pay to get a lot of the good stuff and that was a monthly payment.
Although, I'm used to paying for games...I pay to play MMOs and I find paying for browser games isn't too bad either...I even paid for AdventureQuest and had 2 years of fun with that game. What counts is having fun
Although, if you don't want to pay thats your decision, but its not a lot of money if you see yourself having a lot of fun with whatever you pay for. Especially, as I said that movie theaters are incredibly expensive for only so little entertainment. Of course, not everyone goes to the movies, but its just an example.