Dear Shantanu,
Pl provide some more details in understanding your issue..
what is Container---whether this material has been created by your client itself or by your customer?
(IMP Note:some times your customer also be your vendor and you will supply these goods directly from his place to required Destination--But called as customer in Business words)
I was little confused why Order related Billing here as Suggested By Mr lakshmipathi?
(In Order related billing--There is no Physical presence of Stock--But not in this case)
If this material has been kept at your customers location--any charges he is making on your Client?
If the Material Created By Your client itself and has to be charged-you can very well follow Container as material--Days as BUM and Price as you feel(10Rs)...As suggested By Lakshmipathiji..
Pl Reply on my Queries...
Phanikumar