Arduino + magnetic strip reader + paypal = payment processing machine?

So is the real answer to my question;
card present: 1.5%,
card not present: 3.5%
?

card in present rate is less than card not present for sure, rate is changed by different merchant product, for "online medicine" as example, the card not present could be over 10% since it is high risk product. Same time card in present rate for restaurant some time could far less than other industry rate. "card present: 1.5%" is I make up, we need to wait djMax give us correct rate.

It's just going to be for "services" (rent).