We took a look on Centurion 534 case from Cooler Master, which has an aluminum front panel but internally is still made of steel.

Here is a snippet: "Centurion 534 is the latest case in the Centurion series from Cooler Master. While its front panel is aluminum made, the rest of the case is made of zinc-coated steel (a.k.a. SECC). It is a good intermediate solution for those without the budget to go straight to an all-aluminum case. We took a look on this new release by Cooler Master.



Link: Hardware Secrets