Easy money

Assuming people will continue to buy the same style of fashion for some time.
 
Unless they go by RPG logic where money is limitless and shops would “buy” everything and anything.

It is the perfect plan.  
And Sci-Twi as a bonus.

@Background Pony #14C4  
That’s a bonus.

You forgot about the part where if you are an adult, you turn into a teenager.

What if she sells them all to Flash Sentry?
 
Maybe that’s why he’s been crossdressing so much lately.

@Ainz Ooal Gown  

 
One might even say it’s A B S O L U T E L Y S U B A R A S H I I

Ways for Road to Riches!

Please note: there is a slight chance that repeatedly drawing mass from the Void in this way will cause the portal to collapse, destroying both worlds in spectacular fashion. But you’ll probably be fine. Maybe.

I know there’s a fic about this somewhere…

brilliant!

I find these little scenarios amusing.

@Autumn_Shy  
I guess you are right.Then I’d sell them for about 5% more than their original price.Tidy little profit.

@W.D. Zodayog  
Technically you’d be losing money that way, if you were selling them for less than what you originally paid for them.

@Nittany Discord  
I’d buy the clothes,and sell them for about 10-25% off.Sunset get’s money,and I get money as well.  
Win Win

I’d buy up all of their clothes.

@root  
Then she knows how perverted humans can be IF she did sell her panties….

If her jacket is genuine leather, it could be worth a few hundred or possibly over a thousand dollars. She doesn’t really need to totally strip down every time she goes through the portal either. She just needs the jacket and boots, since those have the most resale value (assuming she isn’t interested in selling her used panties).
 
I think she could make about $400-$2000 on each trip just from her jacket and boots alone. If she sold her panties on some fetish site, she could possibly net another few hundred dollars (maybe more?).
 
I really like this theory, since it explains how Sunset got enough money to survive in the human world when she first visited.

@Vree  

 
Not according to “It Isn’t The Mane Thing About You”.

@Spiritus Arcane  
Well, she could make a cartload of dollars just selling her panties

especially high prize for the worn panties ;P

@Autumn_Shy  
I thought the same but you can regrow tails. And there’s literally no part I can imagine turning into clothes via Conservation of Magical Mass, so this plan still works.  
Regrowing tails takes time? I’m sure there is a spell that can “heal” them instantly. Since they count as a body part. Although who knows? We never learn how much it took Rarity to regrow the one she gave to Steven Magnet. It’s supposedly generous but then again it only lasted for one episode.  
Could Rarity just jump into a mirror and back and generate all the free cloth her shop will ever need?  
What happens if you take extra clothing with you from Equestria? Does all clothing just disappear? Human Rarity’s nightmare! And the end of any plans for human-pony fashion sharing.