"running off" with stuff people sell at a wrong price is the exact same thing as buying and reselling
just because someone doesnt use an item the way you want it to be used, it doesnt make it wrong.
you dont get to decide how other people use their goods/time/money
and just in general, it seems like your view on what makes something greedy is completely backwards
as being efficient in money is the opposite of greedy, and wanting someone to sell something at a lower price because you wont/cant pay the set price is greedy