An infrequent seller with some Q – I do my own shipping etc.

I mainly list books/cds etc. – obviously not those which can’t be but I’ve noticed lately that several of my CDs [music, excellent like new condition] which I’ve tried to list have only been possible as New, New OEM or something of that nature = not Used/Like New or such. And also do all Sony products need to have approval ?= again, tried to list a CD and it was a Sony which I bought YEARS ago = so I can’t provide the purchase receipt which seems to be required. Finally, media mail has increased to $4.15 or so – but the ‘credit’ is still $3.99 – does anyone know why that is? I’d like to figure out how to handle these matters as best possible.