Ask HN: Rewrite outsourced code or refactor it?

Alright, so I'm in a unique mess. Joined a startup, found out that their entire codebase was built by an outsourcing shop (who didn't care much for code quality) and am wondering how to proceed. The startup is about 1 year old. Their codebase is in PHP. There's no in-house team at the moment but we're working on that.

The app isn't super complex (yet) because they were waiting to add most of the complexity once they could get a proper dev team. The code is a mess though, here are some things:

- Inline SQL statements

- Inline PHP inside of on-page javascript

- Pages aren't even W3C validated (or even close!)

- No tests at all

- No data modeling whatsoever

- Tons of PHP related inconsistencies in the data int 0 is false - obviously.

- And much more!

Our choices are:

- Continue in PHP and try to refactor

- Switch to python with Django or something and do a full rewrite.

Underlying db is MySQL. Currently, I'm the only developer but we're looking for more. However, if we do decide to rewrite I'd look for the python variety - otherwise I'd go down the PHP road. (I'm comfortable in both, worked with both in production)

HN Gurus, what are your opinions on refactoring vs. rewriting such a code base ? Everywhere I look people say "Do not rewrite, you'll kill yourself" but almost every time the condition of the code doesn't seem quite like this.. at-least not in the way it's described.