I thought Krispy Kreme discontinued the peanut stick…
But that would be the problem with selling your soul for a set dollar amount, even $500 trillion, seems like Ol’ Satan himself would pull one of his whammie double-crosses like cause worldwide economic collapse, catastrophes, and warfare - leading to such massive inflation that it would render your money worthless before you could carry out your goals with it. He is known for the old bait and switch.
You could get a team of lawyers to peruse the soul contract first, but any lawyer clever enough to outfox the devil would probably already be working for the Forces of Darkness or a record company, whoever had a better benefits package.
If this is just for fun…
I would say the opportunity to torture my ex husband to death.
Well, yeah, I guess the $500 trillion deal assumes that the Author of All Lies gives me an honest deal on my soul (which does occasionally happen in the various soul-buying stories). Of course, how would I know if he intended to do so?
As for someone reselling my soul to the devil (which is a good idea), I guess there isn’t much I can do about it – making my soul non-transferable would reduce its market value.
A time-viewer (just like a time machine except you’re only a spectator, thus avoiding potential paradoxes), immortality, $500,000 a year in 1990 US dollars, perfect health, 20/10 eyesight, the physical condition of an 18-year old . . .
that oughta do it! 
Been there, done that. Used to buy quite a few, in fact, from the desperate and depraved. However, I sold them all off in 1998, for, well, let’s just say a slight profit. Now I’m just sitting back enjoying the view. What can I say, it’s good to be the king.
But in today’s climate, I wouldn’t expect to get much for your soul. It’s something of a buyer’s market these days. I’d wait it out if I were you, see if things turn back around. Then again, what do I know, I don’t even have a soul of my own.
4 easy payments of $59.99 US.
Do I have to deliver it?
If so, I’ll want gas money too.
I sold my kidney to my sister for a bowl of cereal. However, I did not sell her any of the flesh she would have to move in order to reach my kidney.
As for my soul, which one? Khat, saku, ab, ka, ba, khaibit, khu, sekhem, or ren?
“The Bast-Worshipper Soul Value Pack! Act now and get nine souls for the price of one! Limited time offer. No exchanges for souls judged unworthy on the Scales of Ma’at and fed to Ammut.”
“Mmmm… forbidden donut…”
You ask us this, assuming that we all still HAVE our souls. I mean, come on. Mine is pretty valuble, I’ve got alot of offers.
However, if we’re just speaking hypothetically…
Right now I’d sell my soul for an ungodly good massage (every day) by a pirate version of my cutie Nightcrawler (From “X-Men: Evolution”). Mmm… pirates… squee!
Also, I have plenty of other people’s souls, if anyone’s interested…
Some are a little…crappy, but hey. Theyre cheap.
No. This is absolutely serious. Any minute now, Satan, as the Publisher’s Clearing House guy (you just knewEd McMahon was evil, didn’t ya?), will show up on your front doorstep with balloons, champagne and a few little papers to sign. Be wary of all those cameras and lights.
You just supply the blood on the dotted line. 
Bwahahahahaha!
You just think I’m kidding.
Ding-dong!! Yes?