That moment when my graphics card is £50 less than your entire PC...
On a serious note. You can cheap out on the case as long as it's from a decent brand and not a Chinese manufacturer, had a mate who bought a Chinese case and couldn't read the front IO connectors to plug them onto his motherboard. NZXT or Phanteks are good for cases and are quite cheap aswell.

That moment when my graphics card is £50 less than your entire PC... On a serious note. You can cheap out on the case as long as it's from a decent brand and not a Chinese manufacturer, had a mate who bought a Chinese case and couldn't read the front IO connectors to plug them onto his motherboard. NZXT or Phanteks are good for cases and are quite cheap aswell.