Why do developers on IMVU overprice most of their products?

I own an avatar on imvu but she is low on credits most of the time on imvu mostly everything is overpriced so i have to wait until the next day to earn 50credits and earn like that little by little everyday.that takes too long. i think maybe if they lower their prices they will get more respect but i need to know!(oh i also need ways to earn more promo credits without having to pay or join some program)Plz help me!