On AB, I've noticed a lot of vendors will have in their profile "never dispute". Some even say that if you dispute, they will blacklist you, refuse to refund, tell other vendors to avoid you, ect. I'm not a vendor, and never plan to be one.. so I have no idea how things work on their side with AB. When a buyer disputes, other than keeping funds in escrow until the issue is resolved, is there some other negative side effect that happens to the vendors account? I understand vendors want that escrow btc asap, so disputing obviously holds that up... but if you are a vendor.. shouldn't you already expect disputes to happen often due to random slowness with the mail, or because your packs opsec sucked and got caught? Some vendors act like disbuting is the worst thing in the world to happen to them, and there is no reason a buyer should ever do it...
AB keeps tracks of disputes. So it hurts your reputation and makes you seem possibly less trustworthy the more disputes you have.
In the DNM world, reputation and trust is EVERYTHING. So you're basically taking a jab at the #1 most important thing to the vendor. I would rather give full refund than have lots of disputes on my record. chump change compared to the dip in sales from a hurt reputation.