It seems to me that most of the folks who are selling SEM services through webmaster forums like NetBuilders are ignoring the much larger and better paying market for their services -- brick and mortar businesses.
Those guys are spending money on SEM services and they need a lot of help in doing so. The study results above show that they are unhappy with their current vendors, which means that they are likely to be receptive to new vendors.
SEM services tend to be sold very cheaply when they are sold to other webmasters. Brick and mortar business pay higher rates for the same services.