I am often asked by beginners what kind of banjo they should get when they are getting started. And more often than that I meet beginning banjo players who come to their first lesson with a banjo that's not much more than wall ornament. Completely unplayable. They've usually spent about $100-150 bucks and they're bummed it doesn't work. I wish I met these folks before their first lesson. If I did I'd tell them this...
Get the best instrument you can afford
If you start your study of music on a junky instrument you are immediately handicapping yourself. Some people seem to think that by playing a junker this will somehow make them better. These folks are really off the mark. A junker will give you poor technique, sound bad, and fail to stay in tune. Spend a few bucks more and getting something playable.
Expect to pay between $350-$500 for a good quality banjo
I am not familiar with everything that's out there for this price. I started on a Johnson banjo I payed $450 for. I got lucky. I've seen several Johnson's that weren't nearly as good as mine. Stuart Duncan once remarked that this banjo didn't sound cheap. Deering Goodtime models are very consistent in terms of quality. Gold tone makes great banjos that cost around $600-700. Search around and get the opinion of an experienced player before you buy your first banjo.