The gems themselves might not be expensive, but owning a small business that has expanded to a second franchise location in what can’t be cheap real estate means Rarity must be doing pretty well for herself.
Most of the money will go back into the operation of the business, of course – businesses are expensive - much like the Apple family probably churns through an amount of revenue and expenditure over the course of a season that you wouldn’t believe if you’ve never spent time on a farm. However, the profit is almost certainly nothing to sneeze at, even with that.
Rarity can easily be matched in our world to “successful small business owner.”
Wait a second, if the mass-produced dress was also 400… And she had over 200 orders… That’s 80’000…………. I think we just found one of the two greatest sources of income in ponyville.