I think it's well worth it at that price. I saw it in the theater and liked it and picked up The Amazing Spider-Man 3D steelbook on release day. I liked it better than the older trilogy starring Tobey Maguire, especially Spider-Man 3 which flat out sucked.
As for the quality of the 3D, the effect isn't as amazing looking as it is in some other films where you get a great sense of depth and popout throughout, but it's decent enough even if you only really notice it during the big action sequences where Peter Parker is swinging around.
Also, Amazon has matched price in case anyone is interested.