Looks like it's finally time to grab all those games I held off on grabbing because my backlog was already extraordinary, lest I have to find them in a couple years on eBay at wildly inflated prices.
3DS eShop might be a safe bet but aside from the usual downsides of digital, the games are tied to the system, not your eShop account.
But knowing that the console and likely all first-party games will soon be OOP certainly lights a fire under me, as I'd much rather pay $40 for a new, sealed copy of the game than $70 for a cart-only copy of the game off eBay in a year's time.
Radiant Historia: Perfect Chronology evidently went OOP while I wasn't looking, and the Ebay price has already skyrocketed. Argh!
EDIT: And yes, I've got a couple from the eShop (Devil Survivor's 1 & 2 and Soul Hackers), but I prefer carts since they're not locked to my system/account. And who knows when Nintendo will decide to shut down the eShop, just like they did for the Wii shop?
There were not quite so many copies of SMT IV or Professor Layton vs Phoenix Wright.
For example, Pokemon Platinum, is selling used for about 120-150.
Games for consoles tend to follow the same cycle every time. They get cheaper as the current console gets older, then once the new Gen starts, they get really cheap and once you're about one to two generations removed, they get more expensive again.
It has been the DS's time to get more expensive for a while. PSP has also started to get more expensive, though not remotely as much as DS games, since the DS was more popular.