Some costs (in 100s) for an LIS302DL ushield that plugs into a bigger shield:
LIS302DL: $7.59
1sq in PCB: $0.64
Misc passives: $0.30 (two or three caps )
4 pin header: $0.07$8.60
Even assuming Ladyada's 'double part cost' pricing system, we're looking $17.20US (10.90 Euro).
Given that, I think we have a winning idea here. But, what happens they have to buy the $17 board and a shield dock for another $20 or so?