Looking at both sides of the coin here I agree questions should be answered accordingly to establish trust. As a -ve rated newbie myself as a result of not knowing that I couldnt ask a seller a question privately as its an unwritten rule here I can say that some established trusted people here abuse the trust ratings simply for not liking them and dive straight down peoples throats without knowing facts.
This is supposed to be a community forum that welcomes newcomers . And the rules for the marketplace dont specify a price guideline for selling products. I dont. See how a forum can survive without welcoming new people.
That being said escrow is a must , and photos establishing the phone exists is a good idea.