I used to bake a lot of Christmas cookies and
sell them at my Mom's work. If you plan on doing nut tassies every year,
this tool is well worth the investment. They probably wouldn't be hard to make, either, if you have the tools/ skills. (Another great thing to do is bake off the shells and add no-bake cheesecake filling and a maraschino cherry or a little glob of fruit jam)
Edit: Holy crap is the tool expensive on Amazon. It's only $8 direct from Pampered Chef. I got mine as a
gift so didn't know how much it cost (I don't go to the parties).