Lian Li PC-9N
Though Lian Li also produces a lower-cost steel chassis line, the PC-9N is the first full-aluminum version I’ve seen to qualify for a sub-$100 round-up (at $99 and change, of course).
Although the PC-9N's frame is all aluminum, Lian Li still uses a couple of small plastic parts to complete the package, seen primarily as the black end caps of its face plate. Reduced internal material appears to be another part of the firm’s economization, as the PC-9N’s non-removable motherboard tray comprises nothing more than five heavy-gauge aluminum strips.
A look downward at those strips shows that they’re bent into channels for further stiffness, though the chassis still exhibits more flex than we typically expect from a Lian Li product. The case also relies on motherboard headers for fan control; the firm also includes four-pin adapters for anyone who needs them.
Supporting only two USB ports, the PC-9N’s cable pack is both simple and easily installed.