The idea of storing any kayak outdoors without some kind of cover is a bad idea from the start. It doesn't matter a whole lot whether the boat is plastic, composite, ABS, wood, or whatever, the sun will take its toll.
My best advice would be to first find a more suitable storage plan, before investing in a boat. My second suggestion--once the storage issue is settled--is to not limit yourself to a certain price. Do the research and find the boat that fits and that you will be happy with. You will find that the cost of paddling doesn't end with the boat. I don't mean to discourage you at all, but be realistic; this is not an inexpensive endeavor.