Substituting Raisins for Dates

I have been so many raw dessert recipes and they call for dates but gosh darn I'm too cheap to get dates and raisins are so much cheaper. I know there will be some difference in taste but I am willing to get used to it I think, I once made some raw brownies with raisins other than dates but I goofed and added too much water and it was more like pudding.

I don't know a good equivalency for substituting raisins for dates. Does anyone know one and also has anyone substituted raisins for dates in recipes and if so what were your results?