|Items||Rent Price||Discounted Price†||Buy Price|
† Some items are temporarily offered at a reduced price. See below.
There are a few events that occur that determine what Ravio has in stock, and at what price. The very first item that you rent will be free, as long as you do not have enough rupees to afford it normally.
At the start of the game, there are no items to rent right off the bat. The first item unlocked through normal gameplay (i.e. no Item Rental Early is the Bow, which becomes available after watching a short cutscene on your way to Eastern Palace. The Bow can then be obtained for free from Ravio if you answer his question correctly. (Doesn't matter if you have enough rupees to pay for it, the Bow obtained that way will always be free. This means you can get both the Bow and another item for free, even though it isn't useful to do so in a speedrun.)
All the other items, except the Sand Rod, become available for rent when one of three conditions occur:
If one of these conditions is met before unlocking the Bow, it will be unlocked along with the other items. If you visit the Item Shop after meeting one of these conditions and having beaten Eastern Palace, but before completing both House Of Gales and Tower Of Hera, both the Hammer and the Tornado Rod will be on discount at 20 rupees, because they are the items required to complete these two dungeons.
The first time you visit Ravio's Shop after obtaining both the Pendant of Wisdom and Pendant of Power, he will teach you how to use the Quick Equip feature, unless that visit ends up being after you've completed Thieves' Hideout, in which case Ravio will only tell you about the Sand Rod. If that's the case, then Quick Equip will be unlocked upon your next visit.
At the same time, he will allow you to start buying items. The first item you buy will be 50% off. Items you've bought, unlike those you've rented, aren't lost when you die. Buying an item also allows it to be upgraded to its Nice variant in exchange for 10 Maiamai.
After completing Thieves' Hideout, Osfala will return the Sand Rod to Ravio and you will be able to rent it upon your next visit to the Item Shop.
This ability will be obtained on your first visit to Ravio's Shop after you've reached Lorule for the first time, as long as you've already unlocked Quick Equip. If you haven't, then Quick Equip will be unlocked first, and then the Slider Ability will be obtained on the next visit.
Normally, entering the shop when either Quick Equip or Slider are ready to be unlocked will always result on them getting unlocked when exiting. However, deathwarping into the shop allows you to exit without unlocking either of them.
This is used in Low% to rent items without ever unlocking Quick Equip, but otherwise has no practical use.