I'm used to running cards manually in my shop for phone orders, and also for online sales made via gemm.com and musicstack.com, but for sales on my website I realize that capturing cc info and having it on the server is a security issue. Can anyone suggest a payment gateway that allows you to adjust the final price of the sale before it is processed? This is something that both gemm, and musicstack allow, and it is extremely useful. We sell books, records, cd's, and related items. The weights vary greatly, and what we do is list estimated shipping costs, and tell the customer that the actual shipping charge may be slightly higher or lower then the estimate price and the final total will be adjusted to reflect the actual shipping cost. We often end up saving the customer money this way, and in some cases for exceptionally heavy items it prevents us from losing money on shipping. Thus far though I have not found any gateways such as authorize.net that allow adjustment of the total before running he card.

Would it be possible to somehow intercept part of the info before it goes to authorize.net or whatever gateway we use, and we could then adjust the total before the sale is processed by the gateway, but would not send the cc info to our server, so that the security of using a gateway would not be compromised? It would essentially just be delaying the submission of the order to the gateway until we approved it? Any help or suggestions would be greatly appreciated.