Sometime you have to give a low ball price, Bad and missing parts, bad Motherboard, burn screen, water damage, No picutre of the item and or bad or missing art work. It's hard to put a vaule on an item unseen and In unknow condition. This could be a great find or it could be one of those projects that you put in so much money and time into it would have been better off buying another unit.
No offense to the person who is selling this unit. The things I mention do not reflect the condition or the quaity of the game that was posted.
These are just some of the factors I think about before putting an honest offer on an item I am looking at.