You might be surprised. Dishonest people miss out on a lot of opportunities, and they have no idea this is happening. When honorable people pick up cues (like your I'll be fair if you're fair) that a person is dishonest, they'll smile and nod and quietly put you on their "do not trust" list.
People on that list don't get offers that require trust, and those are the good offers.
Aside from that, being an honorable person is its own reward. Being honorable is what you do when nobody is looking.
Accepting a lowball offer, yet in your mind already deciding to renege on it, is dishonorable.
> As an aside, humans are animals, just smarter ones
Everyone gets to choose whether they are a man or an animal.
P.S. I have my failings. But I'm not going to pretend they are virtues.
P.P.S. You're not setting yourself up to be abused by being honorable. There's nothing dishonorable about not trusting people who haven't earned trust, or who have shown they aren't worthy of trust. For example, I wouldn't hire someone who told me their honor is contingent upon other people.