Video Game collection as a hobby is interesting in that it hasnt experienced that big collapse that comics / sports cards / almost any other affordable collectable market has.
The problem with Game collecting is there seems to be more resellers than actual collectors by quite a bit and this will eventually cause backlash in the market as product wont be able to move and which we have already seen with Play N Trade starting and fading quickly, Gamestop buying up smaller chains, and Blockbuster closing up (knocking out Gamerush). Games are not particularly cheap either.
The unique thing about game collecting is that a game can be used with little risk of lowering value (if its already open). I think this will keep the collectable market growing and will maintain price increases on physical items long after they are available digitally, which we are now seeing physical games hold value.
I'm very interested to see how companies like Limited Run Games and other companies affect the market. I know there have been companies collector minded but Limited Run Games is unique in that they purely exist because collectors want a physical copy of mostly previously available digitally games. Their products will be interesting to watch value wise over the next few years.