My Opinion.....

I think to make it in this business, these days, you must be very service oriented. That means that you must be able to stay ahead of the technology curve and offer the services and products before the big guys. If you can do this, you may make it.
Another thing about the product lines...
The one's available through distribution are also avaialble at best buy and circuit city making the profit margins very low. Again you better have a great service dept.
The lines where you can make good money are probably tied up in the Chicago are and most likely won't risk current dealers to sign you on. Fat chance getting Denon (the high end stuff), Pioneer elite, integra, yamaha.
The post above this where the installer wants a business partner is probably the way to go.
That's what I have. I was the installer/owner and I took on a biz guru as a partner.

Jason Walter
www.electronics2you.biz
www.electronics2you.com