I would say $600-$650 for the VPI would not be unreasonable if all is there, and it is in excellent shape.
As for upgrade options for the HW-19, sure, VPI will sell you a brand spankin Platter which would likely run you over $1000.
Things aren't cheap anymore! Sometimes such pops up used, here, Audiomart-etc.
Yes, a better Platter makes an incremental improvement in sonics, but I got by with the stock Platter for a good 10 years, was running a brand new Benz Micro Glider HO and McCormack Phono Stage, and the sound was excellent.
The stock Sorbothane Puck Suspension is OK, better Feet on the bottom of the wood base wouldn't hurt, and like I say a decent DIN-RCA Phono Cable will positively influence the sound. I later went with Herbie's Labs Tall Firm Tenderfeet swapping the Pucks being that the inner Plinth got much heavier with the mods I did.