I think so. I've wanted a development DSi for years (factory is the same, just with a different shell), and I've wanted a dev/factory cart for about as long. I'd been saving for a while and I fixed/sold a few consoles so I was able to cover most of the cost.
Plus I got everything for the same price as I thought just the DSi would be...
I'm not sure how you would go about it, but would it be possible to dump the firmware and such? documenting this stuff would be super interesting!
(Don't feel pressured to do it though. Just seeing it is super neat!)