Shopping

My mom loves to shop. I don't. At least not the way she does it. My mom shops like it's a sport, and she is its seasoned veteran. This little old lady who gets winded so quickly at all of the tourist areas we've visited, can often shop for 5 hours straight without ever complaining that she's tired.
I feel both obligated and doomed to invite her shopping whenever she's around. Since we're traveling together, I don't exactly have the luxury of escaping.
Our last day in Japan, she holds up yen worth about 80 bucks and says, "We should spend this before we get back on the boat. Get whatever you want."
Oh, silly me.  I thought that I knew what those words meant. Or that they actually meant anything at all.
We go into a store that has some really cute clothes. We actually go into several. I can be pretty picky about clothes, and the ones we found in Japan are a bit more expensive than I'm used to, so I want to find something I really love...something I'd wear more than twice.
Unfortunately, I'm not tiny like most of the clothes in Japan, so my choices are limited. Luckily, the last store we entered had a cute little belted shift dress that looked great when I tried it on. Mom agreed. Then she said, "It's 30 dollars?!? We could make that at home. Find something else. We're not buying it."  
Now, I have made quite a few things with a sewing machine, but I have yet to make my own dress. Also, we only have about 20 more minutes to shop. So I tell her, "It's ok, I'm done. I don't want to shop anymore. Let's just get back on the ship."
We constantly play this game. I call it, "what do you want to buy so I can make sure we don't get it?" By now, I'm tired of playing the game. It's hot. It's humid.  We've been walking around stores for a while now, and I haven't bought a thing.  I don't want my last memory of Japan to be of the two of us arguing.  
Before we board, she uses the rest of the money to buy a few small trinkets. We see some nice kimonos, and she insists that I try one on.
It's beautiful, but I'm still missing the shift dress. I would have worked that thing into my wardrobe on a weekly basis.  I look at the prices, and think, wait a minute, this costs more than the dress I wanted.  
And yet, my mom insists it was a good buy.  "You can wear it for Halloween or something."
I desperately want to know what this something is.