I sell trees (and other plants) and have kept my prices constant at what I think is a fair price without noticing any drop in sales. In fact, my sales have slowly, but steadily, been increasing. Maybe I'm missing sales because I'm selling for more than $2, but frankly I'd rather sell nothing than stoop to such lows. At those prices, it's just not worth it after all the various fees, taxes and whatnots have been taken out. Also, you got to ask yourself what sort of customer would be happy to pay $2 for an obviously $20 model?