all you need is a way to get on the internet and pass payment information from PayPal.
then, all you need is the vending machine.
all funds are secure in some remote server with a full firewall.
you have most of what you need to get this working quickly.
make a machine that can dispense the items people want to buy.
work on an internet interface to allow people to charge their account.
the Bank and the credit card companies only transfer funds as people use your machines.