T.S.
Honestly I prefer using local consignment shops. When it comes to buying clothes I'd rather be able to see it and feel it. The only exception has been my daughter's gymnastics leotards. Those are expensive and hard to find second hand so I have used ebay, and been satisfied 90% of the time.
As a seller you can probably make more money selling online versus consignment, but you have to factor in the time and trouble it takes to list, pack, ship and track items, so I don't know that it would be worth it to me.