There is little doubt that given the potential audience advertising on eBay can be very cost effective. Compared to other forms of advertising it is relatively inexpensive. However, many eBay users rarely bother to work out exactly what it is costing them to make a sale.
There are the obvious costs such as the listing, enhancements and final value fees. Also you have to add the charges made by Paypal if that is the option of payment chosen by the buyer. But then you should really also consider what I call the invisible costs. Let me explain, if for instance you buy many of the items that you sell from Flea markets and garage sales what value do you place on your time going to such events and dont forget any travel expenses to get there.
Once you have got your items home you will need more time to research, photograph and list your purchases. Now add the time you spend packaging the items after sale and standing in line to post them. You could easily find that each sale you make on eBay could take an hour or more of your time.
If you really want to know how much time you spend on your eBay business you need to keep a detailed diary for a few weeks. Record...