Buying a saddle tips?

Since saddles are fitted to not only you, but each individual pony/horse as well it probably isn't a good idea to buy a saddle unless you are only going to be riding one horse/pony. If the current sadlle that you use fits more then one pony you could find out from the owner of the saddle what the seat measurement is(from the nail on the pomel to the center of the cantel, so that would be like 17, 17.5 etc) as well as how the gullet is shaped as and the measurement of that so you can purchase a similar saddle that will fit basically the same as the one you are already using.