I know there's a couple rent tracking scripts floating around (eg, Janers posted one some pages back in this thread), but I finally decided to write my own and add it to my list of packages. To get it, you need to first "wotpack update" so the package handler knows new files are available. You can then "wotpack install rents" to get the scripts/aliases/triggers.
Note: a map file is required (not necessarily mine, just so long as the map knows your location) in order for the script to work, as it pulls the room name from your location on the map.
You can type "rents help" to display the available commands. "rents display" shows the entire database, "rents display name NAME" would filter by the provided name, "rents display item ITEM KEYWORDS" would filter by item keywords, and "rent display zone ZONENAME" would filter by location. Some examples are provided in the help message.
The triggers should capture items any time you type list at an inn. It will store them in the database with the character name, room and zone, item name, cost to withdraw, and the time last viewed. It will not remove items from the database when you withdraw (couldn't come up with a quick clever way to handle things stored and rented in packs/pouches), so it's best to type "list" to update things again once you're done withdrawing stuff.
Open to suggestions for any changes (the displays could maybe be tweaked, but they work for now), otherwise enjoy! Let me know if you encounter any issues
