1) you are going to hire someone who can help you figure out what you want and will implement it quickly. This person will have a proven track record of implemented sites and will be expensive (over $100/hour depending on experience and their cost of living).
2) Hire a company with multiple experienced Django developers on staff if you want the site done well and on time. Expect to pay slightly more, ~$150/hour.
3) Hire someone who has done zero Django sites, or a few sites of less complexity than what you want implemented. This person will clearly be tech savvy, understanding what you want and promising the world. They will only have small or incomplete projects to show you as portfolio material. They promise more than they can deliver, because they are naive and possibly still on their Django honeymoon period. They will charge somewhere between $25-$75 per hour and will take several times longer to give you something that just barely works and isn't particularly maintainable.
4) Everyone else. Avoid them.
Find a developer or company who can help you to figure out exactly what you need and has proven that they can implement in a timely manner. Then pay them what they ask. Scale back your expectations if you can't afford their time. Hire someone in the US, but outside of NY and Bay Area unless you live in those areas and need to meet face-to-face.
Random quasi-useless data point: I hired a very good Linux sysadmin really wanting to learn Django for a small/simple Django project. He lives in a "developing nation" (euphemism for "poor") I paid him $40/hr which is about twice what he was making and he picked django really quick and did a great job, luckily he doesn't fall in any of these categories but I realize this is an oulier.
If it is specified as a Django project, then a good programmer who doesn't know Django fits into the Hire someone who has done zero Django sites, or a few sites of less complexity than what you want implemented. This person will clearly be tech savvy, understanding what you want and promising the world. category.
I agree with the parent posts conclusions on that.
I've been doing web facing Java apps for over 10 years, every weekday, for at least 8 hours a day.
And yet, I still learn new stuff every single day. Sometimes not little things either - things that can save hours, maybe days of work.
I've met many better programmers than me. But I know my shit, and I bet I could get a Java webapp up & running quicker than someone like say Donald Knuth, simply because I've done it so many times before.
I've done some Python and Django, but based on my Java experience I know someone with a couple of years experience with it would destroy me if we were racing to build an app. And from the client's point of view, it's always a race because time is money.
Just like me, you'll regret going with a niche like python/django when outsourcing.
As to the argument: A good programmer is a good programmer: Well a good programmer is only if he/she can get the task done. How can you truly evaluate someone how good he/she is? The best metric in this case will be to measure how well the person can deploy the site within the Django framework - after all that's what you are after.
If you pay someone who is cheap but less experienced, there is a very high chance of defaulting. Look at most script lance sites - they are filled with cheap developers from 3rd world countries but from my experience they are pretty terrible to get things done.
Bottom line: You pay for the quality.
If you're looking to build fairly robust web app that you plan on scaling, I suggest either:
1) Recruiting a technical co-founder and letting him choose a freelancer he's closely screened, and then micro-manage the hell out of the project;
2) Hiring a reputable firm to do it.
Either way, pay no less that $100/hr for good work.