Carbon Fiber Printer Bed

Once upon a time i was looking for a printing platform for my printrbot simple after I had upgraded its print area. This lead me down the usual rabbit hole for a flat and available surface to print on.
Things tried:
1. Glass from an old computer scanner - I cracked three before giving up on them, they are tempered glass and will not be cut. After that they shattered from heat shocks.
2. Home Depot Glass Pains - These could be cut but cracked when shocked from heat.
3. Aluminum Sheets - This is a very popular option and I hear it works well. When i tried it i did not get the aluminum milled flat and it was too thin no to bend. I find that metals are too ductile to provide a flat surface. I know that a proper piece of aluminum is the favorite choice of many but with shipping the cost is too much.
4. Mirrors - I got two glass mirrors from reprap.me and loved them, they were the right size and have yet to crack. Best part though, they were $5! Cheaper than getting glass pains