Well I think the larger objective truth about what most people are willing to pay is born out by the market facts: Not much as many games go f2p - even if that was not their initial goal.
For me personally it is more subjective - I think most MMOs pretty much play the same as all the other MMOs (the WoW clones if you will), so I don't think one can really be that much better than another. I'd like to say that even for the best of them I'd not pay more than $45 for the box and $5/month for the sub, but the truth is I wouldn't even spend that because the game play in all these games is so damn bad.
since they all pretty much play the same and have the same underlying game mechanics and most of them are F2P or headed that way then I'd say that is the general overall answer. They aren't worth it for me. I could easily afford it, but don't want to encourage more of the behavior on the part of game companies.
The only thing about this game that half way held my interest was the intellectual property.
[edit] but I thought all these rumors about the game cost from twitter were debunked?