There are lots of businesses that do that sort of thing ethically.
For example-- I used to collect animation art. Some Japanese people didn’t like their animation art leaving the country, and wouldn’t ship overseas. Or the language barrier. Or dealing with EMS/Customs. So, we would purchase through a Japanese company that would bid on your behalf, and then ship overseas for you, in exchange for a fee. So yes, your item would be slightly more expensive, but you were paying to eliminate the language hassle, and to not have to worry about whether the item you wanted was from someone who cared or didn’t care about the nationality of the buyer.
The same deputy bidder company eventually got into a wider variety of goods, to make things accessible outside of their original limited market. Model kits that weren’t released in our area, or clothing items, or CDs/DVDs. (Not the HK R0’s pirated stuff, but the genuine R2’s that were so nichey they never saw a R1 release.)
So, in one sense, yes, reselling can be ethical, if it’s, say, something like a Tonde Buurin alarm clock. Or something.
On the other hand, there are certain companies that pay Large Amounts of Money to ensure that they are the only distributor of Item X in the United States. They do not look kindly on people who either bring in bootleg copies of X, or who try to work around their monopoly on being the sole purveyors of X. That is not ethical.