...There's an exact bundle pack just like that for PC. I picked it up in the UK for something like £8. Unless you're specifically requiring a DS version.
Actually, that's the tricky part, the games aren't that large until you include the voice packs (which really improve games like Sam & Max and DOTT). Even with some major compression, that'd probably be the reason why they couldn't get too many onto a game card. So either they'd have to leave the voices out, or piecemeal releases. Drat.