Abetta or used. I don't know of any other "new" saddle that is under $400 that is worth buying. Wintec westerns are okay, but IMO, Abetta is better. If you can find a Big Horn in your price range, they are great too.
Royal King, King Series, Double T, Hilason, and similar saddles are all junk that I wouldn't take if you gave to me... At best, they just look worn out fast. At worst, they can break while riding and sore your horse. The trees are fiberglass, which warp and crack with exposure to heat and cold. They are often warped out of the box, although only slightly so hard to tell unless you're really looking.