I know what I would do, just have a 10 minute conversation with them about technology. I can easily figure out just where a person is in regards to their development as a programmer just by listening to them talk about what they're paying attention to in the tech landscape. If they don't blink when I mention Hacker News, I know they're on the right track. Do they know what Go is, or Haskell? Do they have an opinion about Node.js?

These criteria are intended to gauge motivation and enthusiasm in the absence of an impressive track record. If they're capable but not highly motivated, then that's fine so long as you're only hiring them to do stuff inside their comfort zone. We have a Microsoft guy just like that. If they're motivated but not capable, then with coaching they'll be able to do anything. The best way to discover someone's motivation is to get a gander at what they're thinking about when they aren't working.

If you're looking for someone who is motivated and capable, you can eventually find someone like that, but you'll have a hell of a time keeping them. Developers have so many options these days that you need to have at least 3 of: competitive salary, decent perks, fun work environment, a glamorous field; in order to hold on to them for longer than a year.

Most companies are lucky to manage one, if they're very lucky two. Since salary is often the easiest thing to manipulate and honestly the most important to the employee, err on the side of paying too much. It's expensive but not having competent developers is far more expensive.