Would be really helpful to see how much you sold the same item for in the past rather than relying on your memory and your customers who all think their 90's gameboy games are worth three times what you could even sell them for. I like the layout and the higher emphasis you put on learning about video game console history, but trying to get a fair price out of customers is extremely difficult. It would be cool if paying for the expert's help had any sway over their original position, because having the secret knowledge about the actual worth doesn't really help when they won't budge.