Come up with a formula

As a dental hygienist, I make 85,000 annually. I want to start selling automatic waterpiks to patients, I see 8 new patients a day for 5 days a month.  I have sold 250 units of waterpiks at 18.50 a unit every 3 months for a year.  I want to increase the price to 20.00 a unit. I have invested 30k  to start up my business and profited 35% for the first year. I want to increase my profit to 50% by the next 12 months. How much will I have to charge to reach my goal of 50% profit?  What will my total income plus profit after 2 years be? 

-come up with a formula

-create graph showing increase/decrease

*change problem if needed