As a preface to the rest of the description, THIS MOD IS DEAD. I was able to add weight to the keys, and if that suits your immersion requirements, awesome. However, after much effort, I have concluded that there is no way to make keys sellable to ANY sort of vendor. I have not tried scripting these transactions, and honestly don't have the time or the effort to. If anyone else wishes to pick up where I left off, you have my blessing (just credit me for the work you build upon).


Anyways:


I was tired of having an inventory full of worthless, weightless keys. It didn't make sense to me that keys that could allow you access to jails/evidence chests/shops would be considered worthless, and their weighing nothing really disrupted immersion for me. This mod changes the weight of each key to 0.1 and adds gold value. 

Unzip this into your Skyrim Data directory, make sure it's active and start playing! No DLC is required.

Update 2.5

Thanks to TalEmper for feedback in reporting the unsellable key issue. I've been trying to add keys to the vendor's items list, but it appears that the game doesn't treat keys the same way as other item types...no matter what I try keys seem to be unrecognized as a vendor item. Been searching the forums but my GoogleFu hasn't turned up any leads. I'm not giving up yet, gonna keep slogging through to try to make keys buyable/sellable without resorting to using scripts. 

For now, a new merchant, Mekral, has been added to the Ragged Flagon. He is located on the platform over the cistern in the Flagon, and as of now functions as a TG fence who sells lockpicks and buys all items, similar to Tonilia. Obviously, he'll only do business with you once you're a member of the Guild. 

Update 2.0


I've changed the values of every key in vanilla Skyrim. All keys now weigh 0.1 excepting Player Home keys, which remain weightless/valueless. Wouldn't want to hawk your own housekey, would you? As a general rule, the changes follow these values:

Jails/Castles/Keep keys: 1000
House/Inn/Stable Keys: 50
Apothecary Shop Keys: 250
Blacksmith/General Goods Shop Keys: 200
Jewelry Shop Keys: 500
Ruin/Mine Keys: 100

Unique Instances:

Goldenglow Safe Key: 150
Honningbrew Brewhouse Key: 150
Sabjorn's Dresser Key: 100
East Empire Warehouse Key:500
East Empire Office Key: 150
Archmage's Key: 500
Mercer's House Key: 150
Calixto's Key: 150
Clan Shatter-Shield Office Key: 150
Bard's College Key: 250
Katariah Master Key: 1000
Pinewatch Treasury Key: 150
Sibbi's Chest/Stash Key: 100
Ingun's Supply Chest Key: 100
Markarth Hall of the Dead Key: 150
Kerah's Key: 100
Calcelmo's Laboratory Key: 500
Dwemer Museum Key: 250
Temple of Dibella Key: 100
Markarth Treasury House Key: 250
Blackbriar Manor Key: 100
Maven's Personal Key: 250
Madanach's Key: 1000

A few chest/cage keys in various dungeons I've set to lower values, as I don't consider them that important/useful from an economical standpoint. Who'd pay 100 gold for a chest key in a moldering, forgotten dungeon? Anyways, this will allow clever thieves to make some decent money with the 'Wax Key' Lockpicking perk.

Post and let me know what you think. I'm happy to get feedback about the gold and weight values, as well as ideas for expanding this mod as I learn more about how the Creation Kit works! 

Cheers

Seadrick.