AI have someone who wants to bring me 300 cupcakes (already baked) so I can frost them. I have a storefront (not sure if that makes a difference in your opinion). Would you do it? If so, what would you charge?

No.Way.In.This.Life! 

Have her come in and you can demonstrate how to do a few and send her on her way.

That's a very odd request IMHO!

NO WAY!!!!!!!  What if she's a hoarder or has 12 cats walking all over her countertops.  When a guest gets a cat hair in their mouth, do you think she'll own up to it as her problem......................nope, she'll say it must have come from your bakery and there goes your reputation.  No , No , No.

AThank you for the replies! That's kinda what I was leaning toward. It seemed very strange to me.