It's worth 60$ because you will easly get 200-300 hours of gameplay for your money before the farming gets to boring, I'd demand more if I was sub but since it's buy and play forever it gives you want you deserver for 60$.
I payed like 30 for dishonored and I played through it in 4 hours, I dont care about achievements though, but I got like 400 hours in d3 without doing achievements and I payed only twice as much and I got 100 times as much for my money.