[adn37]

It depends on what you want to build. Keeping it simple helps.

I designed my last web site in about a month: dev time + learning an MVC framework (CakePHP), not working full time. Prior background of php web dev (non pro). Also, the framework has evolved, and a lot of things I had to do by myself at the time are now in the core.

In the end, what took me time is: back office stuff (end of day jobs, tracking user actions), design integration (we brought a designer in, though), UI (caching and ajax calls to speedup the site, and effects using scriptaculous), having our email platform good to go through spam filters.

Also, even when it seems straightforward, it takes more time than you may think. And coding is just the beginning.

tl;dr: Depends on your requirements and experience. Also, next time you'll be faster.