Sounds like all your potential buyers were doing exactly what singletrackers were offering for a lads computer on here earlier this week.
They are not annoying users. They are making an offer you are not accepting. That is how it works. It is only ever worth what people want to pay. If you want to hold out longer and get a higher offer thats up to you. Speedy responses are people with alerts set up, a budget in mind, and don’t want to faff about. If the item is still not moving a month later you can go back with a higher offer when the seller wants it moved. A low offer also helps weed out the criminals. Use the phone number.
For me I have no affection for the item you are selling and have no interest in the history of a computer for example. Does it work? is about as much as you need to know. For Cars you need the paperwork to check its history/life and that is best done in person.
I have bought and sold from the house, met folk halfway in car parks for kayaks with no issues. I don’t judge people by race or social class or have paranoia issues but am always prepared to walk if necc. Its not rocket science.