It is completely worth it.
I sell thousands of items a month, 80% of those items are either "loss leader" or items I make between a .25 cent - $2.00 profit on. And you are probably thinking "Omg, thats such a waste of time and money"
But here are the facts:
1) This shit sells fast.
2) It ships easy, all of this stuff is prepackaged and sorted. I slap on a shipping label and off it goes in less than 2 minutes.
3) It's reliable money, I'll always have this money coming in. Someone comes in and undercuts me, I can list the product for less, let it become a loss leader, probably push out the competitor, and easily replace this product with a different one that yields a similar return. This always pays my bills. When I had about $10,000 invested in this type of inventory I was making an Easy $3000 a month in profit. Thats when I hired my first employee and while they did the grunt work I could focus on growth and thats how I eventually came to pay Myself 6 figures a year.
I have amazingly high positive feedback, a couple negs won't fuck me over like it will most eBay sellers. I get a couple negs, I can usually bribe them through feedback revision, and poof, those negs are gone.