It really is a choice, one or the other.
Either you happily recommend the best option for your customer, or you give preference to your own items first.
Either you believe in what you sell, or you don't.
Either you treat your best partners better, or you treat everyone the same.
Either you shade the truth when it's painful to do otherwise, or you consistently share what's important.
Either you always keep your promises or you don't.
Either you give me the best price the first time, or you make me jump through hoops to get there.
Earning the position of the honest broker is time-consuming and expensive. Losing it takes just a moment.