While I like the fact that people can get low budget professional services, I think $5 is an insulting amount to pay someone in today's marketplace.
At that rate, if the project takes 2 hours you are paying the person $2.5 an hour. That's slave wages. The site takes 20% of earnings, so a seller is really earning just $4, or $2 an hour.
I believe that, even if it takes an hour or less, it takes advantage of hardworking people.
I believe people working on the site should get at least $10. Five dollars is an insult.