Sandbox Mode?

What about the concept of a custom game mode with infinite gold? Where you can buy any items you want at the beginning of the game and experiment. Leveling EXP would probably have to be increased dramatically to show scaling effects on abilities.

Instead of playing for 20-30 minutes just to see if a build may or may not work the way you want, it could be done instantly. Not only is getting enough gold for a full build very tedious, but if it's purely for experimentation it could end up being a complete waste of time.

This game mode could potentially expand the diversity of builds used on certain champs, while possibly creating some humorous anti-meta builds.

Thoughts?