Once we found a cheap artist for a flier -- using Odesk. (Which has since rebranded as Upwork.)
My sense is just-starting-out graduates of art schools try these sites to "test the water," see all the low prices everyone else is charging, and lower theirs. We got to see samples of work, make changes requests, and ultimately felt like we got professional-quality work at a good price.
Once we found a cheap artist for a flier -- using Odesk. (Which has since rebranded as Upwork.)
My sense is just-starting-out graduates of art schools try these sites to "test the water," see all the low prices everyone else is charging, and lower theirs. We got to see samples of work, make changes requests, and ultimately felt like we got professional-quality work at a good price.