Hi mightysage, and welcome to the community.
I think the second hand clothing idea is very solid, but there are some important elements that you will need to have in place to give yourself the best possible chance of making sales.
The most sought after clothing will be brand name gear, including everything from designer to sports brands. Sure, any piece of clothing has a chance, but brand name stuff is at the top of the list.
You also have to source the products cost effectively, and I'm a bit concerned with $5.25 an item, especially that you don't make mention of any branding?
That's around about new price for what you are describing best I can make out.
Some of the best sources for used clothing can be yard sales, weekend markets, thrift shops and the like. You really need to be buying your items as cheap as you can, then you can list cheaply and let the auction run, which will save you in fees.
I wouldn't be starting a garment that I purchased for 5.25 at 099c, especially not in today's economic environment.
Without really knowing what you have or are purchasing with those tops, then it's a bit of a guessing game unfortunately.