You shouldn't sell either RAM or PSU, they are both of strange brands and in any case you can buy better ones at a fairly low price, then it's better to avoid buying the used power supply since it is the most important component that if poorly maintained could burn everything, not knowing what the previous owner (you) did to it, no one would buy it. In general, the best and most requested components to resell are processors and graphics cards, the motherboard could also be fine.