When I play mine, I end up kicking the legs of the pin while cursing. That must mean it's a good game or I have the leg levelers set too high in the back.
$4,300 is top end, but if it's a nice example, get it. Does it have any mods? If not, that could be your negotiation point.
Also, as for future pricing, who knows. I doubt CFTBL will ever be remade so my guess is the price will only go up or stay stable.
Have fun getting your game and congrats!