Patrick star asks:Instead of Scalpers buying low and selling high why don't they buy high and sell low?

Patrick Star from spongebob is asking

why can't they do that for items like tickets, everyone would love them instead of hate them for that.

for example

lets say a item is 60 dollars,

they now sell it 50 dollars used

and will buy it from a person for most 20 dollars cash or 30 credit,

why don't they do the opposite and buy it for 50$ and sell it for 20 or 30 dollars,

I would love them for doing it