I know and empathize all too well with being honest in your dealings, @scaredycatguide.
I've yet, though, to regret being honest over greedy. A clear conscience is worth more than whatever money I would have made, and then felt guilty taking/spending/saving.
It's good to know that there are people out there who are still striving to be honest, especially in the real estate business. The couple of times I've dealt with an agent, though, have been good, so I might be on the lucky side with that.
My wife has a friend who is trying to move back to Oregon from Florida while finding a property to buy. She thought she had a condo lined up and flew in from Mexico City (where she is visiting her daughter) last minute to look at the condo. She'd previously had someone go look at it who said it was worth starting the paperwork for but she also wanted to see it before going any further.
Concerned that the property might get sold at any time (she was second in with an offer, but it was cash and not contingent on selling her house while the first offer was as well as getting a loan), she made sure to call her buyer's agent to see if the place was still for sale. Her agent told her yes. She got on the plane. From what she was told, the system updated sometime while she was on the flight (the owner accepted the first offer without giving her offer 48 hours to look over).
So, she ended up signing paperwork to put her in second position in the event something fell through with the other buyers. In the meantime, her agent wanted to know if she wanted to sign intent on another property similar to the one she was interested in. At first, he said it was identical, but in subsequent contacts about it, he discovered that it wasn't exactly the same. Appliances and counter tops were not upgraded, and the place would need new carpeting, which meant it probably needed more. She wouldn't be able to see it before she went back to Mexico City, though, because the condo wasn't for sale yet and it was occupied by the current renters. She went ahead and signed up for second position on the first property.
It was just strange how this information had to come piecemeal, rather than being a part of any record he might have access to. He apparently ended up asking another agent who had been by to look at the property. Otherwise, he wouldn't have known even that much.
Yup, I have had some similar adventures. Mine was with a short sale property that the seller was being secretive with his agent about. Long story short, after months of working to get the bank to approval the short sale and being in between homes waiting; the seller got a loan modification and kept the place blindsiding his agent and me. Apparently buyers/sellers can be just as bad.