Do you need English or Western?
If Western, you're not going to find any 19" saddles that are quality. The tree that would be needed for a 19" western saddle would be too long for almost any horse on the face of the planet. You would end up soring the horse because the saddle length. If the rider truly needs a saddle that big, I would consider going with a 20" Australian saddle. You can find them in that size, though you will need to save up to buy a decent one. Australian saddles (with the padded underside, not the flat ones) are shorter in length and will fit a horse's back better in the larger sizes.
You can buy 17" Abetta saddles in the $300 range new. I have a 17" Abetta endurance trail saddle and it's held up remarkably well. It also is made on a good quality tree that fits almost any horse I put it on (their "regular" tree). Chicks Saddlery has some of the best prices on Abettas (though they charge extra for shipping), and buyabetta.com has the best selection.
If you're needing English saddles, let me know what "style" you're looking for and tree size, and I'll hunt some up for you.