Staking question (pokerstars steps)

[KSOT]

Hey I have a semi-busto friend who is really great at not finishing in the bottom half of SNGs and decent at cashing them who I want to stake in the steps as a favor.

The packages you win are worth $12000 and it says they give you $1000 of it in cash. My question is, how many buy-ins would be a fair stake to claim the entire $1000 if he wins. Or if easier, how much reward is a single buy-in worth taking into account both the 100% stake and the amount of work he would have to put in. I figure it can be estimated if you multiply the buy-in by the number of attempts it would take him to beat every step on average but I don't really feel capable of calculating such a number. He's a $5 regular, so it can't be too small... I was hoping someone who was better at math would be able to provide an informed guess.

His PS name is Kyle Rote if his sharkscope would help anyone decide.

Thanks.