Spreadsheet is good for when it benefits you.....depends what side of the transaction your on. When buying you want lower than SS. When selling u want SS. Crazy. But it gives u a decent idea of where to start. You start there and then u barter. Pretty cut and dry. I don't have the link in my phone so I will add later today but there is another site with pricing. They actually show you if the item is going higher or lower in price. I try and use a blend of both. As a rule I come in at a rec or half a key short on all SS pricing unless its an unusual for cash then I play how low can I go.