Still a little confused, So when i start the ATM up, when someone comes in as purchasing Bitcoin, it comes off an Exchange and then i have to put the exchange the cash entered and take my %?
Ideally you would already have an account at a cryptocurrency exchange with fiat money deposited. Whenever someone buys bitcoins via your ATM, coins would be bought on the exchange and sent to the buyer. Once in a while you'd either add fiat money or take them out and deposit them at your bank, later sending the money to the exchange's bank account. Whether you'd add more money to the ATM or withdraw would depend if you had more people buying or selling. Costs/fees cited will be different in every country, take them with a grain of salt. Same with what fees you can get away with.