no other DM's have an opinion?
Well, you know what kind of game you want to run and what your players enjoy, so obviously go with what you think will work over this advice, but here's my personal opinion:
I'm assuming you mean you're going to give these gifts at or near the beginning of the AP? Or is this all going to happen when the players reach book 6? Regardless, I would make sure that all the rewards and costs are comparable between players. For example, you're offering a couple dozen BP worth of stuff for the death of the character. If I were playing him, and my DM killed me down the road over what is essentially money, I'd be pretty disappointed.
I would strongly suggest not giving a level in an unwanted class. This would mean that that character is a whole level behind in his wanted class just to gain a few minor magic tricks which will ultimately become rather obsolete. He's the cleric, to boot, which means that the party as a whole is unable to gain resources such as Raise Dead for a level beyond when they could have gotten them. And the price of this is an unusual skin color. (Which, granted, could be an interesting role-playing aspect, especially for a king, but might not be one that the player wants to deal with.)
If I were running the game, and wanted to introduce the players to the First World early, I would whisk them there (individually) before the beginning of the AP, and present them with a choice between two or three options. One could be "expertise" - a preselected feat that would appeal to the player, one could be "fortune" - the promise of additional gold throughout their lifetime (Which would mechanically be an additional 1/2 treasure reward per level that would appear in the character's satchel or treasure horde. See page 399 of the rulebook.), and one could be "skill" - an additional skill point or HP per level.
The price for all these would be the same - a "favor" that the fey will ask the character later. These favors would take the form of special quests that you give the players at random points during the AP. These should ideally be quests that the character wouldn't want to do due to moral concerns or simply because it's dangerous - don't make them too unappealing, or they will always refuse. Whether the characters realize it or not, these quests will aid the fey, giving them mechanical or roleplaying advantages in Book 6 of the campaign (at which point the players will understand the dangers of dealing with the Devil).
If the player refuses this favor, they immediately lose the gift they chose, as well as suffering what the fey call an "honesty tax" - some penalty that can only be remedied through large amounts of gold, roleplaying, or questing. For example, some of their personal fortune could disappear, or they could be hit with ability drain or negative levels that can only be cured through expensive, time-consuming rituals, or someone or something that they love could disappear, forcing the character to quest to recover them. (be careful with that last one - I wouldn't put the lost person or thing in the First World unless you want the character to have to track them down there, which could prematurely derail the campaign)
Of course, the player could refuse the gift in the first place, which means they wouldn't get the bonus feat, but also means they won't have to deal with the consequences later.
If you're intent on bigger gifts (such as the sorcerer level), I'd advise talking to the player out-of-game to make sure they wouldn't object to it. Ultimately, you know what your players want, and some people enjoy such random, expansive, game-altering events.
Thank you for your opinion. Would love to bounce this off you again. Few details i guess that didn't really click for me when i typed it out.
I Didn't think about the exp thing of the free level. We usally just level up when The DM says too, till we did kingmaker :P Now we use EXP.
The Character that would be dieing is essentially an NPC. He is a retired character that we said would stay in the town, on the ruling council.
I did like some of the idea's you presented. Perhaps instead of a free Sorc level, he will still get whisked away and come back with the age and green skin, and have Fey Blood, but not the level.
Dangit. Wrote up a nice long post, but it didn't submit. Ah well.
If you'd like inspiration, Neil Gaiman's "Stardust" or his graphic novel "Book of Magic" have their own Witchmarkets.
I'd be wary of granting a level in another class, or doing something that might annoy the player. On the other hand, if they're getting something, they'll have to pay for it in some way.
That said, what is traded should be unusual in some way. The entire First World is "off", and the "items", as well as the payment, should reflect this. Taking away all memories of someone's childhood, or memories of someone they know, could be one example of an interesting payment which could have far-flung effects. Take away their good looks (not Charisma, but what if the PC now *looked* very old, or with scabs and boils, while the Fae who did the trading now looks like they do?).
As said above, you know your players best, but anything Fae should be a bit crazy and chaotic.
I can give your more examples of strange and unusual if you'd like, but let the imagination run wild. As long as it's cool and interesting and doesn't alienate or anger your players, you should be good.
Ah. Well, if it's essentially an NPC who's dying, then his death might actually be potentially very poigniant to the players. I'd just be sure they weren't actively playing him to avoid angering them.
The important thing here is that if someone gets something, everyone else should get something comparable gold-wise or power-wise to avoid creating jealousy among the party. Not all these things need to come from the First World, either. One player could get a gift or political boon from Restov or Pitax, another could get something special from an old friend, etc. If you can work it into their backstory and into the future of the party (i.e. getting a gift early on from Pitax creates some interesting possibilities for Book 5), then all the better.