If you are desperately looking for details on how exactly a dress would differ from a designer dress then you have a good amount of reading to do as it is not going to be easy to figure out which one is which as they usually share similar designs however if you have a good eye for detail, you will soon realize that they both represent a completely different variety of fashion and style.
That is right, normal varieties differ from designer but such a difference would only be noticeable to people who know what fashion is all about. If you know how to go hand in hand with the existing trend, you will know for sure what styles would represent what brands. This is why designers have managed to establish their own base of following. If they did not differ in any way, shape or form, they would not have succeeded the way they have in establishing their own client bases.
I have found cute maxi dresses to be slightly cheaper than other designer dresses perhaps because the latter dresses make use of more expensive material to develop their lines of clothing. However, that does not mean all lines that designer are cheap, it depends upon what ones you prefer acquiring. Certain designer lines tend to be more expensive than their counterparts, so it's not a black and white thing as such. There is more to the whole comparison stuff.