I own both of these games currently. Like the vast majority, I voted Star Trek. The price alone would be justification ($3500 is a great price for Star Trek, and not a great price for Jurassic Park), but it also is much closer to you, and given you indicated a one-pin line-up the depth in code on Star Trek gives it more viability.

Young kids do gravitate more when they are over to my Jurassic Park, but overall they tend to play very little pinball. Older kids/teenagers seem more impressed by the light show and gameplay of Star Trek, actually, but my sample size is small.

I think a Jurassic Park would have to be in stellar shape to command $3500, and the distance of drive you indicated is more than I'd want to go for a "maybe" purchase (assuming the condition ended up being less than I expected given the price quoted).