In my opinion, from a life in retail, you must keep a margin of 100% or double up.
This enables all the other niceties people have come to expect like free delivery, returns procedure etc etc. It also pays the bills eg rent, overheads, tax, VAT, staff, admin blah blah.
After all these costs it also keeps the smile from a grimace when folk want showing how to use their new purchase and get it set up.
This was from a different industry but i am certain any shop owners reading this will agree
