Unreal Engineer for Mechanics Prototype

I am in the early conceptual stage of a new game and I want to shape its core feel before anything else. The project will be built in Unreal Engine, so every idea must be proven inside the editor—either through Blueprints, C++, or a sensible mix of both... (Budget: $10 - $30 USD, Jobs: Game Design, Game Development, Game Physics, Game Programming, Game Testing, Prototyping, Technical Documentation, Unreal Engine)