Related: Skyrim: 5 Overpowered Shouts (& 5 That Are Absolutely Useless) Irgnir's house also contains a similarly randomized chest, though they have no quest associated with them and their house will have to be broken into in order to loot it. There is also a chest inside Beitild's house that contains randomized items, though you are unlikely to encounter this unless you have undertaken the Dark Brotherhood questline, as she is one of several targets given to you by Nazir.
If you get into the right position, you are easily able to steal everything that the Khajiit would otherwise force you to pay for, and is a good way to quickly find Soul Gems and enchanted items for leveling your Enchanting skill, as well as potions and poisons that are always useful in battle. Although it should have been patched out long ago, there is a secret chest in Dawnstar, to the left of the Iron-Breaker Mine, that is connected to the Khajiit caravan that stops just outside of the city.