i have an idea for an app and want to better understand the process... reputable developers, costs, margins on a .99 cent app etc. thanks

All the reputable devs are busy and out of reach.

Apple takes 30% from the price, so you're left to figure profit after knowing how many you will sell/did sell.

Development costs can range from less than USD$10k to six figures or more.

You don't provide details on what category you plan on participating in, so it makes anything but dartboard guessing pretty difficult, sorry 🙂