You're going to be doing saddleseat? Both of those are saddleseat saddles.
They're both well made saddles, but both overpriced. Saddleseat saddles aren't in great demand, and anyone showing at the upper levels will buy new.
For either of those saddles they shouldn't be more than $250-$300. I sold one just like that Crosby for $250 a few years ago. I paid $500 for it new, but that was back when dinosaurs roamed the earth....
The Whitman is the better of the two, and will have more padding in the seat and softer and more substantial panels. I think $400 is a fair price to ask for it. That model sold for $1100 new. The minute that Helen Crabtree died, people forgot about the Whitman and jumped to the Shivley. I find the Shively saddles very uncomfortable to ride. They are still "old school" saddles with little padding in the seat, and they are like sitting on a board compared to a Whitman or a L&R.
The Crosby is overpriced per ebay standards, because it's an old-school saddleseat saddle and the saddle snobs now have condemned all of those traditional flat seat saddles to academy or lesson use. If you watch ebay, you can sometimes pick up a Crosby or Crump for $100 -$200. I think they are great saddles. They just are not all padded up. If you dye them very dark brown, they look just as elegant as anything else. Pigskin seats will outlast any other leather, too.
Grip is achieved two ways: Either a soft stretchy leather with a matte finish, or by abrading the finish on a harder and stiffer cowhide. Many of those old cutback started life as Newmarket color, hogprint embossed, and also lightly sanded. They were grippy. Use and also the products used to clean and condition make them smoother or slick. You can roughen one up but then you have to dye or something to make it not look so worn. It can be done, though.
True, lots of people buy new, but the hottest saddles for saddleseat are the Shively MMX $2700, Shively 2000 $1895, and the L&R buffalo saddles $2600.
Jennifer at Showcase Tack sells used ones. Not for $200-$300 though. LOL
The Whitmans are a wide saddle and a straight tree. The Crosbys mostly are, too. The Barnsby trees are more medium width and curvier. The adage is Barnsby will fit more horses than a Whitman will. If your horse is narrow & curvy backed, look for something else.
Adjustable bars are almost a must on Barnsby saddles and are standard on Shivelys. Barsnby always used a shorter bar and hung the stirrups out in front. Their saddles are 1/2 - 3/4" larger than stated size, too. Lots of people bought a standard bar Barnsby 1 size small because of the oversizing plus having that stirrup leather hung up front. The Crosby hangs the leather a little forward, too, imo.