I don't remember lowest price or smallest/largest being there before.

Looking at how the "lowest price" search works, it seems to display oldest level zeros first. That probably makes sense as you can go for "latest uploaded" to get newest, but that then includes those which have sold (and thus aren't the cheapest any more).

The problem I see is that for a lot of the searches I tested with, the first page of results sorted via lowest price looks very unappealing - it's the older "rejects" if you want to be harsh about it. Given that look, I can't imagine it would take off with buyers. From a buyer's perspective I think I would want to see the images with high views and low sales (level 0 or 1) to get the high potential images.

I don't see the point of smallest first - why would anyone care about that? I can see the possible uses of largest first for those users with print applications that require lots of pixels.

I cant see any changes?  I think their "relevance",  actually show quite relevat results though. Good search actually.