Wow! Those are great prices. I don't have one, but I've bought a Graber cart last year and paid double! I love my graber cart. I would say they look just fine to me. If the cart is well balanced, that makes it. Wonder if they do pony sizes?? Have to check.
To me, the shafts don't look all that long on the show cart. I would ask about that. Other than that, they look nice and I don't know why they would have to be pricy to work well, especially if you are only showing a few times a year.