Fan Shrouds would be great. Get Ideas from custom auto wheels. and CNC them. You could sell them on OCN like Candy. For 5 dollars + shipping would be a good start, but you know what it cost to make it.
120mm Fan Shrouds with unique features
Also buy one Case.. Like a Lian Li PC-A05B and cut a really awesome design in it. Sell it but make sure that the person that your selling to send thier case door to you. Then you have a unlimited supply of material. And really good paying jobs. I would ask 80.00 at least for the first one to cover the expence of the first case.