I agree with Strodex
When breeding (especially budget mon), you don't always goes for cheapest. Besides, GTL is live, people are listing any items any time. It can be annoying when something is cheapest when you refresh but not cheapest when you click buy-- you can't buy it.
For your UI suggestion, I prefer if you can design and post, not letting us to imagine with huge wall of text. I'm just not good with visualisation.