It doesn't need to happen. I'm sure you can spare $13 and get a DS Flashcart from a reputable reseller aka eBay.
This is an option for a lot of people, however a few things should be noted - 1. Some countries out there have plainly absurd import costs that would push that 13 dollar ds flashcart from a reputable reseller upwards to more like 40 dollars (Brazil in particular comes to mind) and also, depending on where they're shipping from and to, there's a reasonable chance that they could get caught up in customs. 2. ebay is about the last place I'd recommend buying from, as reputable sellers likely won't risk listing a ds cart (or any other rom cart for that matter) as it's in violation of ebay policy, and potentially throwing their selling privileges on the line, or at bare minimum, there's a pretty reasonable chance that the auction will be pulled before bidding ends. For the moment, I'd tend to agree that it's still the -BEST- option, but I'd personally be all for the idea of cutting out the middleman, and having everything run off the SD card if it's eventually a viable possibility.