I've purchased several of the 0.96" i2c OLED displays off ebay and noticed the price would creep up every few weeks so I tried making my own 3.3V version. To my surprise it worked one the first go. The price for the bare glass off ebay is around $5 and I will sell an assembled and tested design for $9. If you are interested in making your own the schematic and gerber files are attached. If you would like an assembled and tested one then you can grab it at: https://www.tindie.com/products/miker/096-oled-i2c-display/
I have a new 3.3V/5.0V design in the works. It uses a preferred i2c level converter instead of mosfets like i've seen in other designs. Feel free to send me a message if you would like more info. The schematic and board is already done. It just needs to come from manufacturing and be tested.