[mooreds]

I won't speak for Gexla, but from my experience getting into 'PHP' is far different than getting into 'Wordpress' or 'Drupal'. Unless you are subbing for another software dev, most clients don't care about the language, they care about what business value the software will deliver. For SMEs, I don't think there's any ecosystem out there that compares with Wordpress or Drupal in availability of talent (keeping prices reasonable) and free functionality (making it possible to build a very full featured site quickly).

To answer your question directly, I had a couple of years of Java when I did a PHP project (a CRUD system for my book club) and it probably took a few weeks. But I've also worked with Drupal and Wordpress and those take longer to get your head around (Wordpress to a lesser extent)--there are lots of moving pieces, and you have to try multiple plugins to know what will work (and the codebase moves quickly too). I'd budget two months for Drupal, six weeks for Wordpress, and I'd start out with simpler site proposals.