just my thoughts:
fairly sure Jackie Chan did not have a case originally, but that is a decent price for it.
The BONK's are way, way over even for the brick and mortar shops.
I'd still haggle on the bonk games, cut them out of the deal if you have to, but they might come down if your going to leave, you never know. bottom line you've got money and are a guaranteed sale, if they don't have enough customer service to at least listen to your complaints about the bonk games then they don't deserve a sale.
Splatterhouse is maybe in the ball park for brick and mortar shops.
bottom line: you can get all but the Jackie Chan off e-bay for: 60 - 80$
Jackie Chan goes for about $50-100 on ebay right now... TOTAL = $120 - $180 shipped! through e-bay. and that's right now, without looking around and getting a decent price, I found all my games other than Jackie Chan for the prices FQ listed. total there = $55
you'll need to deiced if it's worth it to you to get them instantly through a local place, where you can see and play them first.
I would say $150 is the most you should pay if you can't wait and need to have it, BUT
being you already spent $300 there, $100 is a much better mark of what is Fair IMO for brick and mortar.
I'm sure others will have different points of view of course.