Okay, if I'm allowed one (I'm very convincing), I'm guessing that my 35cm x 27cm x 40cm tall (24 from bottom to the square part, 40 from bottom to arch) cage isn't going to be big enough for ONE budgie? http://www.petmart.co.nz/cart_product654-1-44.html
If so, I was thinking of building a 60 x 30 x 30/40cm tall box out of 2x2's with MDF or ply walls on every side except the front which would be wire mesh. One door that opens up the whole front, and another that opens up half or a third of the front.