I will send them a quote as they obviously ignored all my requests to make best offer. I wont follow up either not into fruitless negotiations. I generally will give a price I am more than comfortable with. Most offers are intentional low balls so will just ignore those. A real enquiry stands out as it is a real person with a real name with a web site you can do a whois on. A real offer is someone that wants to buy your site they won't offer pennies but generally a fair market price as they have done some home work on their end before contacting you. Every enquiry without a real name or priced obviously too low should be ignored.