I bought a Passier Hannover dressage saddle, used, really cheap. It is old, but has fit all my barns fat horses with a medium tree despite being told those saddles run narrow. The seat is hard, but a seat saver can fix that. I have also ridden Wintecs new contour dressage saddle. Incredibly comfortable, adjustable gullet, but the cheapest I have seen them is 900 lightly used. Best thing to do is just go to a tack store and start sitting in saddles so you can get an idea of what is comfortable for you. Cheap argentina saddles suck, but the newer ones are promising. Some of the fancier british and italian saddles are to narrow of twist and I can't sit in them. So test the waters if you can, it is a good place to start.
Think of it not as a failure but as a success in how not to do it.
Don't look in a horses mouth for a gift.