You're the Devil, Gamestop

Today I took a trip to one of the closer GameStops.  The idea was to trade in some of my older games in hopes to either get a new game , Rise of Nightmares, or pay off my preorder for Gears of War 3.  I was really hoping for option #1, but I had to settle for option #2.  What was reaffirmed for me was that gaming is an expensive hobby with little in the way of financial return.  Here's what I traded, what I paid when I bought them, and what I got.

(Wii) Star Wars: The Clone Wars: Lightsaber Duels - $40 - $4.20
(Wii) Castlevania: Judgement - $20 - $5.60
(360) Rockstar Games Table Tennis - $14 - $0.70
(360) Rockband 2 - $60 - $2.80
(360) Fallout 3 - $30 - $3.50
(360) Divinity 2: Ego Draconis - $60 - $9.80
(360) Devil May Cry 4 - $10 - $2.80

Total: $234
Sold: $29.40
Profit: -$204.60

Granted, no one buys games to make money off of them.  The time one enjoys playing the game is usually a fantastic return on investment.  Add to that, Gamestop's notorious reputation for buying games for pennies on the dollar and selling them for a much higher price.  Sure, they have to make profit and there's no guarantee of when the games will sell, if ever.  But the games I traded in were in mint condition and included all of original documentation such as manuals and promos that came with.  I was hoping for a little more, but what can I do?  Half of the games I sold are on greatest hits lists and can be purchased new for $20.  The more obscure games, such as Star Wars and Divinity 2 brought in more money, which makes sense.  While I made enough to pay off my preorder, the total was still less than $30.  I wish I knew of another service that might pay more for my used games.  Anyone have suggestions?