Hello Dan, how are you?
My name is Ravi, I am a self-taught indie developer working on all kinds of things required in game development except the dialogue part, as my voice sucks, haha! I have made many games in the past having advertisement functionalities.
I would definitely love to help you in making your idea to reality. I believe if we discuss more about the project and it turns out to be simple, then we could further decrease the cost to less than $100, as my motto is to always let the client feel that his money has been valued.
Regards