I don't know of a typical salary but what I do know is that if you're serious about the profession of outside sales, I know plenty of people who earn over $100,000 a year. Top money earners in this profession (most likely promoted to management) earn a 7 figure income...over $1 Million a year.
Yes...some companies pay a lot more than others. It just depends on the product/service they offer and other variables.
In any profession, if you want to increase your salary or compensation, I recommend improving your people skills. The more people like and trust you...the more money you make.