Hello,
I am an Australian based web developer and programmer.
I believe that I can create your game for you using the Unity Game Engine, this is a very versatile game engine as it allows games created to be ported to various platforms i.e. iOS, Android and Windows Store as well as PC, Mac and Web Browsers.
I can create your game, but there will be a lot of work involved in it as there is the game to design and program, as well as the back end system for the website (to take payment, and moderate).
I have quoted a very generous price of $700 for this project, although i still see this as being a bigger project than this budget.
If you have any further questions please contact me through this site.