Ethics? or Work Code?

My shift was canceled today, and I didn't know about it until I got in the store. See conversation below:
Me: *running into the store exactly at 12 noon* Hi Jen!
Jen: Hi... why are you here?
Me: I work today
Jen: *at the same time* You aren't working today..
Me: Yes I'm working today!! 12 to 6!
Jen: Noooo
Me: *checking roster...* ughhhhhh my shift was crossed out for 12-6 -_-"""""""

Lucky I live nearby anyway, but what did I wake up forrrrrrr???? And why did I have breakfast and lunch only 5 minutes apart for?????? -_-" ah well.. at least it was the first time it happened to me. My work mates have these many many times already. So I'm lucky enough. And few hours after, I got a phone call asking me to work tonight, which was longer than my original shift yayyy ^^ Lucky me! :) But then... the reason I was called was because the area manager wanted the store be recovered and CLEANED. See that caps?? So I did MASSIVE cleaning (dusting, wiping, etc) of the store. I don't even do this type of cleaning for my apartment unless it's Chinese New Year :P

Anyway, that wasn't the point. The point was, when I was working, there was this guy looking at cute koala & kangaroo small purses for kids. They were 5 dollars each or 15 dollars for 5. He was like "Can you make it $4? I only have 2 daughters..." I really felt bad, but I couldn't give that price to him. I said to him, he could give them to nieces, but those purses were for little kids, and he doesn't have nieces in that age. He then grabbed 2 and walked around the store. I was this close to ask him if he'll still be in Sydney tomorrow. If yes, just go to Paddy's Market and see. I know the same purse is sold around 3 bucks in Paddy's market. I wanted to say to him to go there tomorrow and see, if he can't find it, he can always go back. But then I remember that I am a staff in this store and is it right to push customer away to buy it in some other place? As a stingy person, I really really wanted to tell him. I mean, if you could get it cheaper somewhere else, why would you buy the more expensive one? But if I told him, I felt that I betrayed my store. At the end I didn't say anything to him. I think what I did was right, but I still think about it though :/