We did a significant amount of Wordpress work last year and experimented with pricing (we've since stopped taking these projects). I should really write a full blog post on all the details. Just a side note, we are a C/C++, node.js consultancy but have PHP and .NET developers too (we hired a couple of Wordpress people last year for these projects as well).
What we found is that sites below about $4k we didn't even consider, $4-8k gave us the most headaches and we lost the most money on, $8-12k went smoother but were a slightly harder sell, sites above $12k were much easier but required a bit more sales effort. We wound up front loading every Wordpress site with a designer that would do the layout, get client sign-off and collect all assets before handing anything to development. We did this because one of the biggest issues was waiting for sign-off's and waiting for assets etc from clients, but of course now designer hours go up but that is cheaper than developer hours for us and clients.
Basic rule, the more the project price increases the more you can say yes to clients and make them happy and still make a living for yourself, the low dollar stuff you just can't make clients happy, stay sane and make money. I am sure as an individual it would be better up to a point.
One last point, screen clients heavily especially one that compares you to some teenager or person from another country. It isn't that those people may not be good enough, but it is more about what you are worth then whether they are good enough.