How to design a iPhone case?

[Smileyboy]

What software is needed to start building something like this? I have a few ideas? Autocad is out of my price range Thanks

 

[cambookpro]

If you can't afford the software, you're not going to be able to afford the manufacturing costs with making moulds etc assuming you're making a plastic case.

If you're dead set on making cases, I'd maybe try pouches/slip cases as there is a much bigger margin for 'error' per se.