Still haven't figured out why folks here in WA want breathable waders?
I use a pair of Cabela's nylon waders ($60). I have fished hard in them year round, for 4 years. Lightweight, easy to move in. I layer with fleece pants/long johns in the winter. In the summer, I'll wear shorts underneath or if it's too hot for that, I'll drop the waders and just put on a pair of trunks and enjoy standing in the water.
Got every temperature possible covered and the extra loot saved on pricey waders can go to important stuff... like pricey rods.