There is no correlation between high end games and cases, unless you mean temps.
Case is really dependent on choice. Here:
PCPartPicker part list:
https://pcpartpicker.com/list/B388zM
Price breakdown by merchant: https://pcpartpicker.com/list/B388zM/by_merchant/
Case: Phanteks - ECLIPSE P400S TEMPERED GLASS ATX Mid Tower Case ($69.99 @ Newegg)
Total: $69.99
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-03-30 05:40 EDT-0400