Search for microwave oven and you get a very sensible list of popular microwave ovens, including one they refer to as the #1 best seller. Before you can even sort by price, they ask you to select a product category, selecting which switches to a sort by relevance by default.

If you insist in sorting by price, you do get garbage results (or rather, you get exactly what you insisted on asking for: literally everything in the category containing the words sorted by price). But it's easy to limit the results to just actual ovens by filtering to something oven specific, like the power output. Which ends up giving you essentially the same results as you get when you initially search for microwave oven in the first place.

Search for sansa fuze+ and you get a similarly helpful list. I don't know why you'd ever want to sort by price here: you're searching for a specific family of products and you get there, immediately. In the unlikely case that you want a screen protector instead of the player, there's ways to get there.

Based on those two examples they're doing a pretty good job. And using -- what, exclusively? -- the category menu to find a product sounds excruciating. Starting with a search query is much faster, the category system is available as a filter in step two, at least for popular categories such as microwave ovens.