RW Elephant keeps track of the default rental prices for each of your Items. You'll enter these prices for each of your Items in the Items section of your RW Elephant account.
As you add your rental prices, consider how you'll organize your items. If you plan to rent your Items in a set, pair or group, you'll need to make sure you're accounting for that in your pricing.
Also, keep in mind that you can change the Rental Price for any Item on an Order-by-Order basis.