Pay Pal Concern
I was checking out paypal and i noticed there embedd code is all hidden fields, which also include the price. So of course I tested it and you can change the price and it will process the order, so I changed the price of item priced in at paypal at 74.95 and sure enough i got it for .50 cents. What the heck is going on there!
well, I surely wouldn't recommend tying it into a system that automatically processes the order and ships (in that kind of situation).
However, if I charge 74.95 for a service and a client paypals me 50 cents, I will catch it and tell the client to send the rest. Paypal is not an order processing system it is an e-Western Union, excuse the expression. They don't care how much money you send. The embedded total is a convenience and nothing else.
You can avoid things like that by having a shopping cart that processes the order before sending it on to PayPal for payment processing...and make sure the cart has "referrer-only" type variables (where you can set it to accept orders originating only from the URLs you specify).
I'm with Sketch. You can't rely 100% on any automated system. Someone always will try to go around it so you need to review all orders. Part of the price of doing business.