Selling my old computer on ebay only one problem?

I want to sell my used pc on ebay because I upgraded. Here are the specs: AMD Athlon XP 2000+, 768 MB DDR RAM, Soyo Dragon kt333 platinum mobo, 80GB and 40GB and 10GB hard drives, DVD drive, floppy, GeForce 6800 Ultra 256MB AGP, 56k modem but there's one problem. Due to an unsucsessful case mod accident, I destroyed the side panels so now the case is completely nude except for the front plate. Will this severely decrease the value and how much would it be worth