yes.... there is a HUGE proportion of ignorant buyers. (or potential buyers)
seriously, a guy i know here in Australia bought a second hand iphone, unlocked, in kinda crappy condition for AUD$550 ..... the exact price i bought mine for IMPORTED from the US brand new and locked. and we all know that it only takes about 10 minutes to unlock an iPhone...
just leave them be. if they are ignorant, thats their loss, but its great for us that WANT to sell our iphones