I've not played GA but from what I've gathered it's pretty much the same 'package' as Uncharted 1 was. A good single player game, show casing great tech, good story telling and a solid single player but nothing particually special.
Point is, Uncharted 1 charged $60 without anyone batting an eyelid, yet GA - which is pretty much the same experience - is stretching things asking for $50? No chance. Their pricing is fine here. It'll baffle my mind if something like Street Fighter x Tekken costs less on Vita then PS3, when it's literally the exact same game. Is there a possible justification for asking the Vita version to cost less?
And as I've said before, no one in the UK ever pays £40 for a video game ever. That includes the big releases like COD and FIFA, let alone handheld games lol.