3D Printer rev2 - UPDATED

This is a 3D printer I'm working on based on the Prusa i3v. I had one before but wanted the frame made of metal, linear rails, and lead screws on all axes instead of belts. I couldn't find one on the market with these features so I'm making my own. I'll probably rework the Y axis in the next revision, I don't like how the bed is only mounted on one edge. Also, I'm trying to design it around only using 1/4" / 6mm aluminum, although some parts will have to be from bar stock. I'm planning to make all the pieces on my manual mill. UPDATE: I reworked the bed/Y axis how I wanted it. I also finished up the BOM and calculated total cost for parts and materials... it came out to almost $700. That doesn't include the countless hours of machining this is going to take...