We have actually used one of these site 'Rated People' and to be fair on occasion have helped to keep the business afloat filling the quiet times! For my sins I have had to pay heavily....I have found most people who advertise there jobs on there don't want to pay anywhere near the market value for the work!! And yes always want to cut corners...don't want to use descent materials...usually only have work done as an absolute last resort! Avoid them if you can afford to. You never build a client base as they're always looking to find the cheapest person and so on. Yeah could rant on for ages about it!!