Definitely worth the drive. It should be fun!
I've not been there, but would be well worth your while even if those listed are all that are available. Plan on allowing yourself time to try a variety of instruments, not just those you can afford. That can be very illuminating. You may find that a vintage instrument or their own instruments feel so good that they are worth the difficulty of going over budget. Or you may find that the Rochelle suits your needs for the moment. Or for that matter, if you find that nothing there is enjoyable to play, then you might save a bunch of money by learning that Anglo concertina doesn't suit you after all? Don't expect to play well at first try of course, but certainly for Anglo if you have a chance to sit down with the instruments and noodle about you'll likely know a lot more about what you want from trying them then you ever could by reasoning it out from afar.
And if the cost keeps you to the Rochelle for now, remember that the Button Box (and separately the Concertina Connection) each offer a full credit on the purchase price of the Rochelle purchased from them if you upgrade to one of their own higher grade instruments. So that takes away some of the risk you've previously experienced with starting on a cheaper instrument.
If after trying it and others at the shop, the Rochelle doesn't suit, but Anglo concertina does, then consider a 26 button vintage instrument. I assume you've already dismissed a 20 button instrument, so I'll not argue for it here, although I love mine, it is actually still my favorite. But with a 26 button, you'll have the notes for the vast majority of traditional tunes, and the few absent notes are rarely needed. You might find a good 26 button instrument for less than $1500, which is not within your $1000 budget, but then again not as high as the 30 button instruments either.