Absolutely. When I see people and their insta-block mentality, I just think "that's someone I don't want to do business with". You are driving away customers. How would you feel if Walmart flat-out banned you for asking about a bulk clearance discount, or a sketchy price match? Better yet, how about if your Lego B&M store kicks you out for asking for a break on a damaged box? Just about everyone is looking for a deal, and the definition of such need not be the same for both buyer and seller. Have a little tolerance. You nearly have a point, but don't make the mistake of assuming this person is calculating your profit margin in their head when they ask. That's not their problem. Maybe they just have a budget and a need and are hoping for the best. I had an older rare sealed star wars set listed last year and got a generic message asking if I would take barely over half the BIN price. Sure, I rolled my eyes, but then I made a short professional reply declining the offer. The story got interesting (and suspicious to me) when I was basically begged to reconsider by a 12 year old kid looking to spend all his birthday money on the one set he wanted most. Taking the story at face value, I replied again in a much more friendly manner, apologizing that I couldn't accept his offer, and suggested he search for used sets instead. Three days later I get notified his grandpa agreed to pay for the difference, and I got my full asking price and made a kid really happy with no hassle whatsoever. No need to jump to conclusions about who is a true fruitcake and who needs to be blocked from your "shut up and give me your money" business, people.