Should I Keep This Star?

Only if it's a low run. The SN is too high,IMHO.
John1

Spend it, or keep it in a holder locked away carefully so your grandchildren can wonder what the heck you were thinking.

Whilst I appreciate that my knowledge is more limited than the other responses you ahve already received, I view that star notes are in general worth keeping (if you can afford the outlay)

Yes lower serial numbers, and teh better the condition the better the price. However as star notes are in relatively lower print runs than standard notes, their rarity and therefore value will (read should) only increase.

the question is whether the investmeent (here $10) is worth the (possible) reward in teh future.

It also depends what you collect, if you collect.

have fun

I like star notes a lot and since they don't come around often, I'd keep it. Put it in a large book for a few years to help smooth it out.

Just make a note of the page # in your inventory list. I put it between a couple of white sheets of paper, so the ink from the book doesn't rub off onto the note.

Now if you work in a bank or a place that gets a ton of crisp notes you can look through, then I might spend it, if I found a ton like that, in that grade.

And good condition is a really low grade for a note, but I don't think that is what you really meant. Here is an explanation of the grades:
http://www.pmgnotes.com/grading/grading-scale.asp

And for 2006, there are only 3 districts (B, C, and G)) that have star notes, so I would definitely keep it then. Try and get a star from each district.