Since caribguy brought it up, maybe the next time you visit the client you could kick a pipe loose in his bathroom. Then explain that there's a leak in there, and maybe he should call to get the plumber to come out -- shouldn't cost him more than $10.00 an hour, right? Oh, and maybe the plumber can also finish the Web site for that same $10 an hour...
If the customer laughs at you, walk out, and let him get a $10 per hour Web site elsewhere. You, meanwhile, should immediately raise your rates to between five and ten times that rate. You may find that you get better, more-organized customers that way, as well... and can afford to have fewer of them.
Basically, in addition to short-changing yourself at that $10 rate, you're setting yourself up to "get no respect" by pricing yourself just slightly above the burger-flippers at Mickey-D's -- and a lot cheaper than plumbers.