The Wayfarer's Inn

How much wealth were we able to bring out in the bag of holding and Sol's haversack?

Gaderon has the Cleaver of Set he would be glad to be rid of. If we didn't bring out enough loot, Gaderon could perhaps give up his Staff of Power to get his levels back. His other magic items don't seem that valuable.

Kherim can contribute the Horn of Blasting

On the other hand, we can start with Ahi first and then he can do some of the restorations himself. That would save us money, although the risk would be on him and the party, of course.

If Ahi is willing to take the risk, you only need to pay for his restoration. It still means four spells as he has lost four levels to the vampirettes, but the cost is reduced to a mere 200.000 GP - something that you're able to pay in cash when you sum up your loot from the tomb so far, plus perhaps a bit of gold from Gaderon's personal treasury....

I'm willing to go for a hybrid solution. Maybe not just those 4, it depends on the price structure. So, how do we compute the cost?

Another important question: do we get xp for retrieving treasure and selling it?

if Gaderon has a personal treasury, he will be happy to "dip" into it to get the restoration done.

Sir C, would "Remove Curse" be applicable to the curses we successively found in the Tomb?
If so, Ahi would try a Remove Curse on everyone in the party before going back to the temple.

I have reviewed the spells for Ahi and Kherim. While doing so, I found Restoration and I see nothing there about aging the caster 1 year or doing a system shock. Sir C, is this a house rule? The aging and the system shock are pretty harsh, and I don't see them even in a wish spell.
If these are not there, then Ahi will happily cast all of them beyond the needed to give him back that ability.