How much money could I get for used pokemon games?

How much money could I get if i sold used pokemon games such as, Heart Gold, Black/White, Diamond/Pearl/Platinum, Firered/leafgreen, emerald/ruby/saphire. I am wanting to know how much I would get if I sold it to gamestop or if it would get more on ebay?How much money could I get for used pokemon games?
Gamestop is an amazing place to buy or rent games, and is the biggest international game retailer. That said, they don't buy games for much :P Not unless you're good at haggling. You'll probably want to take the Ebay or personal sales route. If it were me, I'd start the bidding at $10-15, maybe even $20 for the newer ones. If you choose to go to personal sales, you might even be able to sell it at the buying price. Just ask around to see who's interested.

As a standard tip, this is a good starting price range if you sell it online (not by Ebay or other bidding sites):
Like new - 85-90% of original price.
Very good - 75-80%
Good - 65-75%

And if you choose to haggle at Gamestop, they'll no doubt start at like $10 or something. Say something along the lines of; "Ooh...nah. Can't do that. What about $25?" And go from there ;)

EDIT: After reading other answers, I forgot to mention that if you have an older Pokemon game (such as the legendary Red/Blue) then you can get a LOT for them. Somewhere in the $80-100 range possibly.
Game stop is terrible, it takes over thirty minutes to trade in games, they only give you in store credit, and they rip you off on all your trade ins,they also fingerprint you. If i were you i would sell them independently and separately, that's where you would get the most profitHow much money could I get for used pokemon games?
when i was a little kid i played pokemon games all the time! And now i decided to sell my games and i sold them on ebay, people bought them for alotta money for the old blue and silver versions!. So if you sell them on ebay your going to make a lot of money :)
You wouldn't get $20 for the lot at gamestop. I would try to sell them on craigslist or backpage. And as for price you could get maybe $20 for each DS game and $12-$15 for GBA games. Except emerald which you could ask $20 for since its a higher demand game in the series.How much money could I get for used pokemon games?
Sell the gba pokemon games on ebay because gamestop wont take the gba pokemon games but I don't know if gamestop gives you this much for pokemon White/Black still but they gave me $17 a piece for pokemon White/Black and I think $10 for diamond.
at gamestop they would only give you about $3 for the old pokemon and for the new games they would give you about $10 but on ebay you should get a little bit more then what you would get at any game store.
7 bucks