I completely agree with the rational for a hanger but I think you're over exaggerating the degree of deterioration when sitting outside. You could paint the plane every other year for the cost of hanger storage. Cockpit covers keep the plastic from wearing as much as hangers do as long as you use them. There's a million arguments to get a hanger and I assure you I can't refute them all. If I had the money and was keeping the plane long term, I'd rent the hanger space. Otherwise, it just doesn't make sense for an aircraft only worth ~$20k.
