I don't know about the FN assemblies, But Browning lists the Pro 9 DA/SA/C&L assembly for $140.00.
I myself won't be buying one. Because frankly the "Cocked and Locked" zealots are not thinking a three position lever though very well.
FN thought long and hard about whether or not to go with the Browning three position lever and I believe, they came to the conclusion that in most cases the stress of quick reaction response, would lead even trained users, to inadvertently decock the weapon while releasing the safety, during an emergency fast draw. Taurus had this problem when they went from the old 1911 type safety, to a three position with a decock on the old Taurus 92's and 99's in the late 80's and the problem is not uncommon amongst users of the much vaunted H&K USP family who elect to carry DA/SA cocked and locked.
Yes, I know that suggesting one should be trained well enough, with the pistol they are carrying, that DA/SA shouldn't matter and that if they're close enough you don't have time to pull the hammer back, DA vs SA, isn't going to matter anyway, is pretty much heresy around the gun boards now days. To hear the SA zealots talk one has to wonder how anybody ever got killed with any pistol that wasn't a 1911.
FN will be offering a SA model, for those that just absolutely have to have it.