This is a 2 story 2x4 multi level that i made. The girls on top and boys on bottom. You can open the top lid in one piece or it's divided in the middle so you can open just one side if you choose.
Both front panels can open downward for cleaning.. I also made hay racks & tunnels out of extra grids.
To make this cage, It cost around $180 and was fairly simple to make..