>I'm not saying that a SQL Server back end is never the right solution. Of course it is. But I think that the genuine way to do that would be to tell the user that up front and let them bear the costs while the project is being put together (not at some future time when they may not be ready to deal with it).
In that case, what is your preference for the back-end?
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)