I've been with the hobby for a long time :-) I've yet to need more than 5 channels.

The typical compelling arguments for a high end radio are memory for more models, mixing that's not available on lower end models, or an actual need for more than the basic 4-5 channels. If money is an issue, a basic 4 channel, or the new 4 channel computer model Ken mentioned, can actually go a long way. It's unfortunate, but way too many people try to convince beginners that they should go out and spend $300+ on a radio before they even know if they'll like the hobby.

Quite often it's better for a beginner to go out and buy a basic radio and use it for the first couple planes. If they decide they like the hobby, and can afford it, they can upgrade at that point. Little to no money is lost with this approach because the cost of their first radio was about the same as a flight pack.