I have the following flash carts for sale. both are about a month old and in perfect condition and include all packaging(nice little wood boxes) and everything that was included with them. I'll throw in a cd-r with the drivers so you dont have to hunt them down. I have positive feedback in the feedback forum if you'd like to look.
EZ-Flash III 1GB of storage-retails for $165 im letting it go for $100 shipped
EFA linker 256MB-Extreme flash advance retails for $90 letting it go for $50 shipped.
both are fantastic units and DS compatible. I needed to get rid of a few systems to keep my spending down and my GBA was first to go.