Very ethical of you. Personally I look at buying and selling things very dispassionately.
Value is relative. When there are lots of buyers for a scarce object it’s value goes up and the reverse is also true.
I wanted a Stingray for years but there were few for sale and many people that wanted one. I bid what I could afford and constantly lost out on bids. Was the seller unethical? They were getting as much as they could so not really.
In the last 12 months there have been more 2EQ 4H’s on the market (colour, year, neck composition didn’t matter) so I continued to bid and got one at slightly less than my previous top bids. This was its going value! It was what someone was willing to pay at the time. The seller was happy. I was happy. In a few years I may sell it for more or less depending on circumstances (both personal and wider economic). There is no morality unless someone takes pleasure out of someone else’s misfortune.