More of a question?: artists_beware

More of a question?

I saw this in a previous entry about every commission big or small deserving the same respect/attention. However, if you take on some super cheap commissions, as many have noticed there is a $1-2 sketch commission frenzy that has been on and off since last year.
Examples:
http://sennkoh.deviantart.com/art/Pencil-Sketch-Furzone-102880113
http://demandincompensation.deviantart.com/art/2-Commission-Luxray-110373820
http://winterweather.deviantart.com/art/2-00-sketch-commission-03-111871427
http://www.magnorth.net/commissions/sk-luka.jpg
http://www.furaffinity.net/view/1950674/
http://img.photobucket.com/albums/v244/SAKKET/1buckxample.jpg

If someone says that you did the character wrong and asks you to redo it, should you? Should there be a preliminary sketch even in this instance? Would you offer a refund? Do you think people who take such cheap commissions should just be spat on because they're making it harder for you to get commissions? I just want to hear opinions on this.

More of a question?