Rather than giving a very specific suggestion, I would recommend a larger philosophical position: change what you have control over.
For example, Gamestop's used sale policies are almost entirely outside of Publisher control. You can exert a little influence -- and I recommend that you do that -- but by and large used markets exist in every industry and it would be nigh impossible to quash it.
By contrast, game budget is entirely within your control. 100%. Every penny you spend on the game's budget is your choice. As such, it is within your power to make a game that costs as much as 100 million dollars, just as it is in your control to make a game that costs 100 thousand. Lower budgets could allow lower retail prices. Mr. Pacther identified the lower initial prices of DVDs and CDs (10-20) as reasons why those industries are not suffering as badly from used sales "stealing" revenue. As such, lowering budget would allow you to lower retail price which should supress cost. Remember, this is entirely within your control.
Another example: gameplay mechanics. As with budget, the gameplay mechanics are entirely within the control of the developer/publisher. 100%. And as have been mentioned in this thread, some games seem to have lower trade in rates, while others have higher, and these tend to follow predictable patterns. Games with social and/or multiplayer value tend to be held on to longer. Examples include Mario Kart, Call of Duty, and Wii Fit.
Other options: look for other venues for your products. For example, Arcades allow for a theatre-esque "first release" of a game. If a game were released in Arcades first and then later released on home consoles, this would allow for additional revenue streams. This, however, is not entirely within a publisher's control; game developers have (I believe consciously) quashed the Arcade market in the US, and revivifying that market would take concerted effort from multiple publishers. Nevertheless, the concept works in other industries and could theoretically work in this one, in some form: release the game to a venue outside the consumer's home first, then offer a "home release" later.
To loop back to my original point: focus on the things you can actually control. You can't control rental markets: Nintendo tried and was laughed out of court. You can't control Gamestop. You can control other things, though, and you should concentrate on those.