We are trying to integrate Authorize.Net into our process but it needs to be a two part "checkout" one covering the cost of the item being purchased which we know at the time the customer is filling out credit card information, and then another cost that we find a few hours later to cover shipping charges.
When a customer places the order we want to send them to our website to pay for the order by credit card (DPM) which will do an Authorize Only transaction for the cost of the item they are ordering. Then after we pull the part and pack it for shipping we will get the shipping cost and want to do a Prior Authorization and Capture via AIM to include the freight charges. Is it possible to submit an amount change like this after the initial Authorize Only? Is our only solution to do an Authorize Only for an amount larger than the cost of the part and once we know the freight charges to a prior auth and bring the cost down to the total charges?
We are stuck because we won't pick the part until the customer has provided credit card information, and we won't know the cost of shipping until we have picked the part.