Pinnacle: Pardon me but there is a lot more to all what you summarized in two lines.
PCI Compliance and PA-DSS compliance are two different things. PA-DSS is applicable when you own the shopping cart code and you host either on your own...
In my opinion this whole PIC compliance is a complete money making scheme. You have not include the crucial expenses that the PCI Compliance brings to the table.
If you are a retail store and performing less than x number of trans...