I bought mine (used) from a rep 3 years ago. Before she came to the barn, she had me take very specific photos from certain angles of my horse’s back, then she came out with a van full of saddles to try. We narrowed it down pretty quickly to which tree would fit him and she watched me ride in 3 models of saddle with that tree. Again, this is for a used saddle, so my choices were limited to the used stock she had, but when I picked my favorite, stuffed/fit it on the spot and I’m super pleased with my purchase.
The rep I worked with was awesome, but she does travel all the time, so you do have to make a fitting appointment months in advance.
If you are buying new, you can either go full custom, or they do have a semi-custom (Pret-a-porter) line as well. But even with the semi-custom line, you cant just order it from the website. To make sure the saddle is the best for you and your horse aa rep will need to come out. pricing is what you would expect for a well-made custom saddle.