" Don’t sell gigs that will require days of work from you. Like “I will develop a full web application for you, for 5$” or super-tight schedule ones like “I’ll illustrate and design a logo in 1 hour”. "

I also made this mistake, but it was great learning experience. Even though my prices were the highest among similar offers, most of the buyers belived that they basically hire a full time Software Engineer for this money.