1. buying the cheapest groceries you can reasonably find
2. trying to get the highest salary you can
3. literally any time you try to get more for yourself
that's a weak list from which to conclude that greed isn't a problem, especially since in the case of 1. and 2. someone's making money off you, the person who's supposedly greedy in these scenarios.
2. is literally you making money off someone else. That someone else might not also be making money off your work - you might be selling services to an individual for their personal consumption, or more commonly, you might be doing that through an intermediary (employer) that connects consumers with producers and launders the guilt of demanding more money.
1. Do farmers count as greedily making money off you for trying to get the highest prices for their produce from distributers and retailers who are trying to compete for customers with low prices? Yes but that's good! Every player in that supply chain is optimizing for themselves and it ends up working pretty well for everyone. Maybe you think farmers are too rich and should not demand so much money for their produce because greed is bad?
Consensual trade between rational actors leads to both of them benefiting. Before capitalism, the ideology which focused on property rights and individual freedoms didn't really have a name...
if that's the one where you get to own things then there wasn't trade before capitalism, because you can't trade things without ownership. is that what you're saying?
you listed
1. buying the cheapest groceries you can reasonably find 2. trying to get the highest salary you can 3. literally any time you try to get more for yourself
that's a weak list from which to conclude that greed isn't a problem, especially since in the case of 1. and 2. someone's making money off you, the person who's supposedly greedy in these scenarios.