I think this is a good idea, seeming as many people always ask (I'm sure you've got this to Ernie) How much should i sell my Bakugan for? Well, I think your system is good. Any easy way to manage it, without making your head explode, is run it with a point system. I would say your starting base should be $5 since the majority of stuff in stores runs between 5 and 6 depending on where you go (never mind the 3 packs, most people arent buying them as much now, because they may only have 1 or 2 in there they dont own already, so I've noticed those are becoming less popular) So I would base it off of 5 and then run a point system after that. Which is almost entirely subjective, but without creating a computer program to do it for you, you dont want to over work yourself. (If I have time I will see if I could make up a quick one though to help you out)Anyways, I would put it on a point system such as:HM Darkus Dual Hydranoid:Based at 5Add a point for Darkus (again the popularity of the attribute gains a point)Add a point for Dual Hydranoid (popularity of the marble)Add 2 points for HM (scarcity of the HM's out there) Each point adds $1So, I would total it to $9(This was just an example, I know the price of this changes...just an example.)But that's essentially the system. Use the points to either drive up the price or down...Hammer Gorem:Based at 5Deduct a point because this marble sucksDeduct a point because this one has a crappy paint jobETCSell price $3And so on. This way every marble could be changed easily. Especially if you ran in through a Microsoft Office type program that updates it for you, all you'd have to do is delete a point here or there.Well, there's my idea. Any others???