Explain, please? A pannier that is ultra durable in many senses of the word and will last a long time so you don't have to buy a new one seems like a good low cost pannier to me? $20 a year seems pretty cheap if I have them for 10 years and they will probably last longer than that, VS say $50-80 every year or two for cheaper ones that aren't as good or waterproof or durable.

I like to look at long term costs when talking pricing because short term only really matters on goods that aren't needed to last or do anything super well.