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