If you're going to claim to sell vintage video games, I at least expect you to have an adequate collection of original Nintendo games. I'm not asking for Paper Boy here, just a few Mario Bros. THEN you could call yourself a "video game dealer".
Sure you've got loads of other games for PS2 and Wii and XBox but if I want to buy Tiger Woods '05 for $5 I can go get it at EB Games. Give me Kirby's Dreamworld and I'll give you my business.