Benjie Franklin had a great fall, and all the king's horses and all the king's men ...

It's not a very expensive attraction, which is good because it's not a very large cave/mine. The info inside is definitely interesting, but somewhat limited (the "Nun's Poem" about halfway down on the left is hilarious). Read the dining hall description of the monk holes as well. Also, the cream tea in the shop/cafe was pretty decent. If you exit the cave and go up to the church/mausoleum up on the very top of the hill, you get a nice view of the area in all directions. But other than it being one of a billion little English villages, I wouldn't say there's much other reason to go to West Wycombe (if you google for West Wycombe, the Cave homepage comes up before the Wiki article for the town itself, for example).

If you had an extra couple hours to burn on your way driving up the M40 from London to Oxford (or if you wanted to avoid driving through Slough on the M4 on the way to the Uffington White Horse or something), I found that someone from the Boston area would find it interesting to see the connection to Franklin, anyways. There are definitely better and worse ways to spend a few hours in the UK though.