At least not when we′re talking about goods of that magnitude!

Never!
(I nobbled the MQ early on)

I bet Mankar Cameron would have paid good for it though. The creep would probably try a double-cross though, to weasel out of paying. I am sure other private collectors would buy it. You could even sell it to Jauffre!

Hmmm... Here's a mod idea.... "Sell the Swag." You can sell the amulet, and... 1. If you sold it to Jauffre, then rumors start flying about a mysterious Hero of Kvatch, and Oblivion Gates start popping up all over the place. 2. If you sold it to anyone else, Blades agents start showing up, following you around, and asking probing questions.

Joking aside, I like that. When you play a character who is a thief or an assassin, it can be hard to reconcile having that silly necklace in your inventory all the time. I learned to get around it by removing the essential tag with the console, and putting it in a respawning container. But being able to actually sell it in the game, and then even having people coming to look for it, would be cool.

I'm stuck for any reason that anyone would keep it. You can't use it, you can't sell it. The only thing you can do with it is hand it over to Jauffre. Whatever your character's motivations, wouldn't you want that out of the way? You already know that a bunch of assassins are trying to get hold of it, but you don't know any safe way to negotiate with them, so keeping it is presumably dangerous.

I'd second the idea of a mod that provides some options. (or is it at least third by now?)

I have not had a character who would want to keep it either. Most of the time I have never wanted to do the main quest, and just tried to pretend the tutorial never happened. So typically my first move with a new character would be to drop the amulet in a barrel in the IC Market District and just go on playing like they never saw it to begin with. It would also be nice if you could give the amulet to Jauffre and be done with the main quest. Just say no thanks, that hero stuff is not for me. (I know you can do that and ignore the main quest. But you are still being told/expected to continue it. I would like if Jauffre says "ok, good job citizen, we'll take it from here.") With my characters who have wanted to do the main quest, they typically went to Jauffre early on (with only a few side trips to look at shiny things )

I actually think that might be the basis for a pretty good mod. The player could switch sides in the crisis by offering the amulet to Mankar Cameron. An NPC could track the player down, Jollring-style, and whisper, shifting his toothpick to the other side of his mouth, "Psst.The Boss'd like a word wit youse. Get in the car if ya know what's good for ya." Mankar "The Finger" Camoran offers the player a job as an "enforcer" in his organization. And before the player knows what they've done they're caught up in a whirlwind of double-crosses, shady dames and back-alley intrigue that makes the paranoid political infighting on Vvardenfell look like kindergarten.

Or you could just sell it.

I could imagine Baurus eventually tracking the PC down. He even already has voiced lines that could be useful, things like "You're a hard one to track down..." and "The Emperor saw something in you, trusted you..." If you give him a flimsy excuse: "Really? I never would have guessed."

There should be an option selling it to Umbacano! Where is that mod, people!?