Think about the order of magnitude:
(1) An average 2.5% transaction fee on a $100 dollar e-bay transaction is US$2.50 in revenue.
(2) The cost of sending someone a "paper bill" in the mail (fully amortized) is approximately US$2.00, or 80% of the revenue from a $100 sale.
(3) at $8.50/hour, a minimum wage worker would expend >80% of revenue by spending 15 minutes to help you.
(4) A "quick fix" with a paper-trail (2+3 above)quickly turns the transaction negative ($2+2=$4>$2.50) at the margin.
(5) Since every fix is an instant loss, profit maximization implies "fix minimization"--at least as one component of strategy.
(Disclaimer: This is all made up math.)