Riight...
I do prefer the stack-pot Jazzes. Have done since the late '80s They're not everyone's cup of tea, esp ones withe the [i]real[/i] vintage wiring, i.e., prior to '62. These had resistors as well as the tone caps and the circuit was wired slightly differently, iirc. This, couple with the fact that these earlier versions had 250k/250k pots, contributed to a signal with discernably less ouput. This was the reason that Jaco ripped that ciruit out and just went for the VVT setup. I have a bass wired like that (out on extended loan right now) and whilst I do like it it doesn't have the oomf of my other stackers, which have 250k/500k pots throughout and no resistor!
As to price? Well, the Gallery one is a bit steep. 2nd-hand, the going rate is between £650 and £850. Again, it depends on how authentic you want the bass to be. Some of the Custom Shop ones go the whole hog, with nitro finishes, matching headstocks and the string mutes included. Have look at USA; there's some up there right now.
As with any instrument, ask to try it. But my view is £1200 is too steep and you'd be better off waiting for a bit as they are popping quite regularly on the s/h market.