I think it's a bit different coming from the other end, unfortunately. Craigslist has come quite far without what we would all consider "design" (though that's debatable - functionality
is design). Alas, traditional aesthetic design has never found its way to Craigslist.
As a designer, you might find scripts / examples / tutorials that work, but without understanding the entire web stack it's going to be difficult to even get an "MVP" running. If I asked some designer friends to go set up a server to run Django, they probably wouldn't know where to start (though some would hunker down and truly figure it out, they would be the exception).
My opinion is that "decent design" is easier to achieve than "decent functionality". Don't get me wrong, I'm all for professional design and appreciate every minute that goes into it - every single app I've built over the past few years was started by an awesome designer (even my no-revenue side projects).
For the developer, though, things like http://twitter.github.com/bootstrap are helping us get very far into an app without asking designers for favors (or paying someone).