Bought a bunch of new games over the past 11 months since the last time I did the "I wonder what my NES games are actually worth" and compared it to vgpc (it's as good of a quick/easy rough estimate as any), so I decided while bored at work today to not only add the new games but update the old ones -- they've almost all went up, some significantly. A few have dropped, but usually like $1/$.50 on a sub-$5 game or something.
Since this time 11 months ago, my collection has went up roughly $970 in average worth.
And then there's all the arcade stuff that I don't wanna think about

Edit: And $200ish on SNES... but I know I've gotten some SNES games that haven't gotten logged (the only one I was sure of was SMRPG). I really have to do a full audit later this year once I print off all my NES covers and alphabetize everything.