https://www.pcgamer.com/this-thermaltake-case-with-tempered-glass-panels-is-only-dollar30-after-rebate/

The days of having a pay a premium for a case with a tempered glass side panel are now firmly in the rear view mirror. There are several affordable cases that now use tempered glass instead of acrylic, and if you can catch one on sale, even better. To that end, Thermaltake's Core G21 mid-tower is available from Newegg for $29.99 after rebate.

It's listed on sale for the next six days for $54.99, down from its $69.99 price, which itself is pretty reasonable. However, there's a $25 mail-in-rebate available that brings the cost down from reasonable to downright cheap.