I do agree that the lower hourly rate you seek/accept/charge to clients, generally the worse quality clients you get. Clients that want lower rates tend to be more clueless, less experienced, more tight-fisted with cash, more likely to try scope creep on every milestone, and they tend to concentrate too much on rate but not on total hours or quality or other positive qualities. They're more likely to think hard things are simple and simple things hard. This latter point especially is true of most non-technical clients, but in general it's more pronounced with the cheapskate/rate-focused clients, I've noticed in my experience.