Bicycle Turn Signals

I am about ready to create my own bicycle turn signals. Here are my study materials.

Bikes are skinny and I want my lights to really stand out and show the direction I intend to turn. My plan is to have an easy dismount so that I can place these on my bike trailer, as well. I found turning indicators on eBay that originally mounted inside of rear view mirrors and are shaped in an arrow pattern.

I want to see if I can build this set-up for under $25.00 (US). Stay tuned for my complete Instructable.