Hi Dean,
The most important question you need to answer is "what do you have on the top?" If you have natural teeth or crowns & bridges on the top, then you're going to be miserable with a lower denture. Considering going for all-on-4 teeth if this is the case. On the other hand, if you already have an upper denture, then going for a lower denture is not a bad idea. Typically, all-on-4 teeth is more than double the cost of dentures. In my practice I charge 15k for an all-on-4, but based on your dentist's pricing, I'm guessing he charges around 25-35k. If you'd like to learn more about what exactly all-on-4 teeth are, you can read my article on is all-on-four the right choice for me? Hope this helps and best of luck.
Ali Jazayeri DDS