$1,500 is the bottom, IME. It will get you a decent new Shen, or a slightly better used Shen, which is probably the better deal. For your goals, you could also consider a used Eminence or NS Design CR for less than $2K. The Shen, of course, is the only one that offers a true URB experience and tone, but, you seem to be paving your own path so maybe you'll be one of those players that like and use the EUBs differences to your benefit. Stranger things have happened. Truth is stranger than fiction and all that.
Also, if you like the Brian Bromberg, Gary Burton type of tone, rather than the Ray Brown type of tone, you're more likely to be happy with a EUB because Bromberg, et al, have their basses setup almost as if they were FBGs, really low, low action, very little volume. One more push for getting a knowledgeable jazz bass instructor to help you navigate those preferences in a well-educated manner before you make a decision.
You should seriously consider your air travel needs. I don't play many non-local gigs, but when I do, I really, really, really miss my URB, so I've been jonesing for a removable neck URB that I can fly without much hassle. The thing is, once you buy a URB, you can "enjoy" it - if that's the accurate description of the pain it inflects on the innocent - but it doesn't get along well with most of the rest of the world.