selling and buy resources

i think we should be able to buy resources at outpost. (for about 10 gold) cursed cannon balls can maybe go for more but i do think the range of 50 - 100 per. i also think once your crew is going to get off and you have a stacked ship full of supplies you should be able to sell back to the merchants for half price you bought it from. this would save time and help people get going much faster!