Quit bumping the thread. Store the DVDs at room temperature. For best results they should be kept in individual cases, if not then storing them in spindles will do. As for which wears out faster between +R and -R, it doesn't really make much difference provided you are using quality media (ie Taiyo Yuden). As for why DVD - format is cheaper? It depends on where you are located in most places the prices are pretty similar but the - format has been around for longer and that is why it might be cheaper in some places.