Ah yes, the good ol' "make claims the opposing side can't possibly (dis)prove".

Because judging from your OP, I can clearly see that that was in your classifieds listing.

On another note though, the process of a keybanker is quite autonomous, coming from someone who was in the business for a while. Most times you have a bot or a person buying your keys for a consistent amount, and you want to buy other people's keys for less. The house analogy doesn't exactly carry over to this, but try to imagine that it was your job to sell houses for X, and to buy them for less than X. Then up along comes someone announcing to the whole world that they're selling their house for way less than X. Are they asking the world how much to sell it for? Maybe, but not without also stating they're selling it.

So, this person selling has just announced it to a lot of people, and you know you're not the only person buying and selling houses for profit. Naturally, you jump on the deal. I mean, who wants to be the person who had the chance to get a deal like that but passed because it might have been a mistake. You wouldn't leave $20 on the floor in case it's a fake, you'd still check it out. Better safe than sorry, in a way. So you add that person, you talk to the person selling their house, you pick up that $20 bill. Does this make you the scum of the earth trying to scam off ignorant people? No, it makes you a competent business man.

Let's just work through the couple possible scenarios for someone going for that deal. The first scenario, let's call this "Scenario A", is one where you add the seller, through some magic he adds you back, he is for some reason actually selling the key for 1 scrap, you buy it, and you've made great profits.

In the second scenario, which we'll call "Scenario B" (I think you might start noticing a pattern) You add the seller, and he ignores your add. He might have been actually selling to some lucky buyer, or maybe he made the mistake of inputting the wrong number. It's not unusual for keybankers to be ignored, so overall, nothing of value is lost.

In Scenario C, the buyer adds the seller, it is a reverse phisher, the hopefully not completely incompetent buyer doesn't fall for the bot's ruses, and proceeds to block them. Again, nothing of value is lost.

There are some other strings of each scenario, but the end result is the same, and besides a possible string for scenario C where the buyer does fall for the bot and gets a virus, (but I'd hope no one actually falls for those godawful bots) there are no negative outcomes for the buyer. So I think it's completely reasonable for someone to add someone selling keys for that price.

P.S. I seem to have forgotten that there was also trade requests being made. It changes nothing though, adds and trade requests are the same thing for this trade.