Ammo Truck?
Everything is priced at the estimate price for simplicity.

To access the fleet hanger right click the Orca, and select Open Fleet Hanger.

To split a stack, hold shift while you drag a stack.

Click that stack to see that stacks estimate price in the lower right of the inventory window. The stack price also appears when you mouseover a stack, along with the per item price.

Holding Ctrl while you click allows you to select multiple stacks.

To pay for the items select the items to see their estimate price. Then right click my name and select Give Money, with the estimate price in the amount, and optionally what you bought as the reason.