The last Resident Evil game on the DS even had no ability to delete a saved game, effectively making the game one play per sale.
Second to last, actually. This is an important distinction because the game you are talking about, Resident Evil Mercenaries, is an arcade-style action game, where the only actual progress to be deleted is earning high scores and unlocking additional levels and characters. The most recent Resident Evil game for the 3DS, Resident Evil Revelations, is a story-based experience and does offer the option to delete save files.
The first-sale codes are a little more controversial in the gaming blagosphere. No publisher has denied a single-player experience to players who do not use the included code, but multiplayer and downloadable content is often tied to it. For some games, this is not a big deal, but for others, multiplayer is a major component of the game. However, the codes are not "darn close" to the MSRP; the MSRP of new games is typically $60, with used games going for $40-$55. The codes sell for $10-$20, with the goal of making the price used (with all multiplayer and DLC in tact) the same as the price of a new game, thus encouraging gamers to purchase a new game.
There is an interesting debate concerning whether what EA is doing is ethical or not. On one hand, we have the First Sale Doctrine, which guarantees the reselling of used products and might(?) be violated by EA's first-sale codes. However, the First Sale Doctrine was created with things like houses and automobiles in mind--things that naturally tend to lose value over time, due to wear and tear, or things that maintain value only if money is spent on repairs and renovations. Thus the decrease in value is tied to its use.
Software, on the other hand, does not depreciate in value in the same way. While the physical media--box, manual, and disc--are vulnerable to wear and tear, the bulk of a game's value comes from the game itself, which comprises of the software on the disc. In general, the game either works or it doesn't; a game will hold full value as a game until the disc breaks, at which point it will hold virtually no value.
What this leads to is a used market dependent entirely on the game's popularity. Games that are less popular suffer a multiplied loss: less copies will be sold new, and, because the price difference between used and new is so great, a higher percentage of copies will be sold used, further hurting its sales. The invisible hand certainly has something to say about the justice of unpopular games causing losses, but in an industry as young as gaming, any factors that increase the risk associated with developing a game (typically over 2-5 years, costing hundreds of thousands to millions of dollars) can be seen as negatively impacting the development of games as an art form. (Recently, independent games made on small budgets in far less time, have become prolific; they often represent the riskiest, most innovative, and in some cases, most artistic expressions in gaming.)
Is it fair for games to be subject to a popularity multiplier? Maybe. However, the gaming industry is a different framework than what the first-sale doctrine was established for. I realize I have been playing the devil's advocate throughout most of this comment, but I believe the issue needs to be explored with hard economics before we can draw strong opinions on whether it is right or not for publishers to discourage the sale of used games. It is possible that the used games industry puts games into the hands of far more people, improving its legitimacy as an art form, but it is also possible that used games are a primary factor pushing publishers towards sticking to established franchises and neglecting innovation in favor of reliable sales.
