English Standard Version (ESV)
My first reaction to this story is always the same -- Lighten up, Peter. He just wants in -- he's just a little confused.
But I think Peter isn't reacting to the motive so much as he wants to set a precedent. Think of what happens to the early Christian movement if people start to believe that you have to buy your way in. Imagine how many people are denied access, or don't even try and gain access, if they see the grace of God as another commercial endeavor, some good to be bartered and sold to the highest bidder. The rich would occupy the loftiest positions, and the poor would be left out once more. It would be the opposite of the radical Gospel that is proclaimed.
So Peter rebukes the effort to buy one's way into the church, and he reminds Simon, and all who can hear, that the grace of God is not something to be bought and sold. Our money is no good when it comes to grace, for God's economy works completely differently than our own. We can be rich in grace and poor in money, and we can be poor in grace and wealthy in money, and any combination of the two, but our dollars and cents will never change the way we are seen in God's eyes. It is not money that is the root of all evil, but the love of money, and if we love money (whether or not we have it), that will interfere with our relationship with God.
So may we come to God as we are, so often poor in spirit, and receive what is lavished upon us by a generous and loving God.