Machined Cubesat Chassis (10x10x10 cm^3) made of aluminum

I have to realize a cubical rigid aluminum structure, roughly 10 cm x 10 cm x10 cm like #-Link-Snipped-#. For PCBs, I know that there are manufacturers where you can order a number of boards designed by you in ORCAD or Eagle. About aluminum structures manufacturers I have no idea. Is it possible to order a structure like that cubesat chassis, I have wrote about, for a total cost of less than $500? Has anybody, on this forum, made or had it made a rigid aluminum structures like the one I want to build? I have no idea how difficult is to machine such a chassis.