I will never forget my best friend, after learning that I was selling on eBay driving up to my house with his car loaded with all sorts of junk, like old tires, a rabbit cage, clothes etc. and asking if I could sell them on eBay for him.
I told him, as politely as I could," Pack up your crap and give it to the garbagemen"
Why do people think they can make a million dollars selling on eBay all the junk that they have no use for and would generally have thrown away?
As I pointed out, Glenda supported and Todd confirmed, you will find that in the long run, it is generally not worth it financially, so at the very least, set a minimum to pay for your time so you are not totally out of pocket.
What you may find as a TA however is another line of items that you can add to what you normally sell, so I look at it as an investment for the few that I choose to work with but I generally turn down more requests to sell than I accept.
I get about 2-3 requests every 2 months. Alot are to sell collectables such as crystal glassware, sometimes prints (art work), often used musical instruments, furniture and electronics.
I started dabbling in comics last year as a TA for someone that had over 500,000 in his inventory but there are far too many people selling them and most have resorted to selling them in bulk.
Malcolm