It can cost pennies to lift Cables from being directly in contact with anything.
I will take a wild guess and suggest my Lifted Speaker Cable method, took approx' 30 minutes to achieve, inclusive or searching for items I never search for, i.e Cotton Reel and Drawing Pin.
I would say the cost incurred (Speaker Cable not Included) £00.03p.
That is the same type of cost I try and generate when buying used CD's at a Yard Sale.