Pricing > only one price upgrade no matter if customer uses text / text and image / image only. Does this work?

 Hey all,

we are wondering how to do the following: There are options for prices for custom text, custom images and of course your own library. Is there any option that the customer is only charged once no matter how many items he adds? We offer front and backside customization. For the frontside the price is already included. We also show the backside and we want, that the customer is charged once when he places something on the backside no matter how many elements (image, text etc). Does anybody know if this is possible?

thanks!

tm