Average full time agent makes 12 to 17 sales per month.
Average Sale pays $275 up front (considering you offer free equipment to half of your clients.)
Average Sale pays $30.00 per month residual.
Let's be conservative and say you are selling 40 or 50 hours per week, getting 12 sales per month.
You make (12 x $275) $3,300 per month up front.
Every month starting with about the third month, you are adding (12 x $30) $360 to your monthly residual check.
So if you are asking how many months until you make $8,333 (100K / 12), we would take $8,333 - $3,300 up front which is $5033 which is how much residual you would need to make in addition to the up front money to reach 100K. Then if we divide that by how much your residual would increase every month ($5033 / $360), we see that you need 13 months to build the residual plus the initial three months you need for residual to start showing. So I would say in 16 to 18 months you could be at that level.
These numbers are legitimate and conservative except for one big problem: most agents do not sell for 40 to 50 hours per week. Or if they do, they are not building a business. They don't track their prospects or plan their schedule. So all of the numbers above assume you are actually going to be out in the field 40 to 50 hours per week and are going to be organized, collecting your prospects' information and planning your schedule.
Consider one other thing: Let's say you hit fifty accounts in five months. You will then have a lot of installations and customer service to do. You might end up hiring some independent contractors to help with this. Obviously, these business expenses will set you back a bit. A more realistic target for a really solid $100,000 per year business with some good people on your team and solid stream of $8,000+ per month profit would be 36 months. If you are a super salesman and very scheduled, you could do it on your own faster. But to build a real business will take a little longer.
I hope this helps you understand how the numbers work and how long you would take to earn six figures in this industry.