I set the bar at one Feat, per level, per person (able to throw Wish or Miracle) approached.
Thus, a 3rd level character could approach an archmagistress, pay her for a Wish spell, and thus gain a Feat
Then, the 3rd level character could approach the High Cleric, pay him, and gain a Miracle, and thus a second Feat.
And then, yes, the 3rd level character could approach the Great Sorcerer, and pay him, and thus gain another Feat through the Wish spell.
One Feat, per level, per person approached.
However, if that character then went back to the archmagistress, and paid for another Wish, that character and the archmagistress would find that the Wish simply failed (the archmagistress still loses the experience, and the fee must still be paid.)
Ditto the High Cleric and the Great Sorcerer.
Furthermore, the Archmagistress would NOT grant the character a Feat through a Wish spell, unless the character was VERY convincing and said some VERY clever and persuading things.
Ditto the High Cleric and the Great Sorcerer.
You want to know why?
How would your archmagistress character feel if, when she looked out the window of her manor, there was a line of adventurers standing beyond the gates?
Your archmagistress knows that each and EVERY wish is going to cost her dearly in experience points.
And just who are these people out there?
They are strangers.
Perhaps, they are enemies, or potential enemies (to a mage or magistress, any spellcaster is a potential foe.)
And perhaps she does not wish to be bothered at all hours of the day and night by strangers banging on her front door!!
The likely result of this is the Watch appearing and asking everyone to leave ... immediately.
The next time anyone shows up, they will be arrested for vagrancy (or whatever the Watch can think up) and jailed for the night.
The NEXT time people show up, the Watch will arrest them on charges of trespassing, spying, and other serious charges, involving fines, whippings, a long prison term, and perhaps even hanging.
The Watch will do this because the magistress is a powerful person in the city, and powerful people are influential in the city politics.
This archmagistress has the favor of many of the top politicians in town, and perhaps she is one of the top politicians herself.
And she has better things to do with her time - and her experience points - than to waste them on a bunch of uninvited strangers loitering around on her property.
Now, if the audacious 3rd level character goes through special channels, winning the favor of minor politicians, worming his way into the goodwill of important people, and otherwise brownnosing it, he ... might ... be granted an audience with the archmagistress.
And then, and only then, could he proffer his request.
He had better have a GOOD reason for his request, or he will receive the cold shoulder, and after the formalities are finished he will be shown the door.
And he will NOT be able to obtain an audience with that archmagistress again.
A better idea, for the 3rd level character, is to make no request at all, but instead to attempt to win the friendship of the archmagistress (which won't be easy.)
Once he has won her friendship, she will be more kindly in her dealings with him (but will still not grant that Wish.)
However, if the 3rd level character forms a deep and strong friendship with the archmagistress, so that eventually he can enter and leave her manor at will, and all her minions and servants know him by his first name, and everyone in the city knows this particular fellow is favored by the archmagistress ... and then if the intrepid adventurer must undertake a deadly quest ... then PERHAPS the archmagistress will grant him a Wish, and thus a Feat.
Then, if he survives the adventure, he can return to the manor of the archmagistress, and renew his relationship with her (along with all that entails and implies) and being now 4th level he can gain another Feat from a Wish cast by her.
And that is how I would handle gaining Feats by Wishes.
Of course, there is always incredible luck.
If a character of low level gained a Ring of Three Wishes, one of those would grant him a Feat (the other two would not, and he might well waste them trying to obtain more Feats - such is the price of greed.)
A character drawing the right card out of a Deck of Many Things could gain three Wishes, and thus one Feat.
Certain Tomes and special magical items might confer a permanent Feat (and many, a temporary Feat-like ability.)
However, the real way to gain one free extra Feat per level via the Wish spell (or more than one Feat per level, if more than one high level caster is involved) is for the character to ROLEPLAY, and to WORK, and to STRIVE for the goodwill and friendship of these high level NPCs.
That means sweat, blood, and tears, and then more sweat, blood, and tears, and frustration, and pain, but ... the rewards are worth it.
If a player has two characters, one high level and one low level ... and the player is considering having his high level character throw a Wish to give his low level character a Feat, his high level character becomes an NPC under my control.
This is temporary, until the Wishing for Feat matter is resolved, one way or another.
I honestly think the attitude above is reasonable, concerning this matter.
I would LOVE to have one or more free Feats per level.
And because I would want that so badly, I would make the effort and the sacrifices necessary to obtain what I wanted ... and a whole adventure could be woven around my efforts.
If I succeeded, I would be thrilled.
If I failed, I would try again somewhere else.
No adventurer ever gives in and quits!
The intrepid adventurer (and his or her player) can never be put down!
