Personally, I would make my feedback no worse than to say "Naive eBayer because..." followed by a plain description of all this fuss about 'immediate collection' (which wasn't even specified in the original listing) and the relisting at elevated price (they should have set a reserve, to begin with, but obviously don't know how).
A one-off incident of misunderstanding is not the same as a pattern of behaviour which could be described as dishonest. Make an un-barbed piece of feedback and you can expect to be treated likewise. If a pattern of 'misunderstandings' develops on a seller's account, other eBayers will be able to work out for themselves what it going on.