Are they also buying?  I wouldn't jump to the conclusion that selling stuff that you've been hoarding for years (or maybe inherited) is necessarily a trade or business.

Folks I know who do this sort of thing usually specialize in something they know (like maybe stuffed animals in your case) and grab every great deal they can find at thrift stores, yard sales, flea markets, swap meets, etc. to resell on ebay for a profit.  Ding!  Profit motive gets you a long way toward the nebulously defined "trade or business."

Rick