"It's not on sale"

We were buying a backpack for Bradley when Emily ran to that little spot...you know the one - where they put the toys down low for your kids to want and beg for while you stand in line.  Shockingly, E found a toy that she let me know she really, really wanted and lifted it way up high for me to see. 

I said, "oh, Honey, it's not on sale today, maybe it will be next time we come."  She said "o.k. Mom", put it back and came skipping over to join me.  As I turned my attention back to the cashier, I noticed she looked amazed.  "wow!" she said, "I can't believe she accepted that!"  The lady behind me chimed in, "my grandson would be crying right now, I'll have to try that one...."  So, I left the store smiling, thinking how I would share my genius-level statement with Chris over dinner... my pride imagining the headlines..."Waxhaw mom discovers one-step method to stop tantrums in the store!!"  ha ha.  Well, my smile faded quickly, even as I buckled E up in her seat.  It hit me that I have not taught her the difference between wants and needs, I haven't taught her about contentment, I haven't taught her about idols - I've taught her to look for sale signs!!.... man, I did it again - I keep missing these little "teachable moments".  I thought about it on the way home and when we were parked in the garage, I turned around and explained to her how I should not have told her she couldn't have the toy because it wasn't on sale, but because she didn't need another little princess; she should be happy with the ones she already has..... yadda, yadda, yadda.  I ask if she understands what I'm saying and she gives me the thumbs up.  I'm feeling really good about my better-late-than-never speech as she runs in and starts playing with her little princesses that she has been reminded of.  But then she looks up at me and says, "Too bad Belle wasn't on sale!!"  
sigh. 
I'm thinkin the Lord is working on my pride, huh?