There are a few things about the description that you need to consider. Fiberglass trees are cheap, 28 lb is a light saddle - not stout, and the term "Quality Leather" really doesn't say a lot- who would say "leather like cardboard".
$150 is very inexpensive but it just may work for you for a while and you should be able to resell it for what you paid when the time comes. Just be sure it fits you and your horse or it isn't worth anything.
I'm not trying to sound discouraging but just point you in the right direction. Never buy a saddle because the price is right, buy because it's a good saddle and it fits.