I'm wondering how can i "buy" codes from boutique.
May I use my oeufs? Or my oeuf will be converted in "points" at the end of each month like EK on eurokiddies?

You can buy the codes from boutique by using your PayPal account (prices are in Euro)
You can't pay for the codes in 'oeufs'.
At the end of the month the 'oeufs' won't be converted to any points you can than use to buy the codes in boutique, but they are very useful when you are trying to be at the top of Monthly Clasement