To a point, yes.
Like anything there is a point where it just goes too far. When an individual goes in a buys 2 LE items and resells one or both there typically is no issue. When it gets to the point where they game they system to the level where you almost can't buy one if not through a reseller then it has gone too far.
Concert tickets are a great example of the gone too far scenario. You quite literally can not get good seats to most large venue concerts unless you go through a ticket reseller or own seat rights.
The big rub is there is really nothing you can do about it. "Fair" is an abstract concept that just does not exist in nature and especially not in capitalism.
To quote WOPR "The only winning move is not to play".
I agree, there are situations where I feel it goes "too far." And I agree that is, to a large degree, subjective.
However, ultimately the market will bear what the market will bear.
I started my business 20 years ago selling mostly CDs on eBay. At that time, I sold most at auction. My cost on most was between $1 to $3, and I started bidding on most at $5.99. Some would sell for $5.99. Some would sell for $100. Some would sell for $5.99 one week, $100 the next week, and back to $5.99 or somewhere in between the next week (for the same title.)
I felt by starting them at a low price, I was being fair. Nobody had to bid higher than they wanted. I was happy with the $5.99, but sometimes I got a nice surprise.
I also learned the hard way about all the fees, the risks of losing money on transactions (which happens regularly) and other pitfalls.
And I saw some sellers who would start their common items at $100 or put them at fixed price for even more (when the fixed price feature became available.) I did not think that was fair, but if that was their strategy, so be it. I'll use my own strategy which I think is better for both me and the customer, and they can hold onto their item for years. Maybe it's worth it to them when it finally sells. Who am I to judge?
There are, to be sure, valid collector markets for just about anything. When I was a kid, there were books published that were price guides for coins, baseball cards, etc. What goes into making something valuable is partly supply and demand, partly desirability, condition, etc.
Today sites like eBay have become in a way default price guides. But unlike the books that were published annually, they fluctuate frequently, in real time, and are, for that reason, more accurate. They also reflect fads/trends.
At one point, I thought I'd expand into Disney stuff. I bought a few pieces from one of the outlets. Results were "meh." I decided to stick with what I knew.
But if I went to a record store in Pittsburgh that had 3 copies of something on clearance for $1 each because they thought it was worthless, and I knew I had sold it in the past for $100, you can be sure I bought all 3 copies and gave them a whirl on eBay.
There are people who are more than happy to pay these prices because, as I suggested earlier, it's a lot cheaper than traveling to get it where it is. I've had collectors send me messages offering thousands of dollars if I could find xyz. (It only happened once, LOL.)
The line is finer, IMO, when it comes to newly released merch. Again, I'd probably disagree with WDW's limit of 10 per person. That seems high.
OTOH, there are so many instances where we (retailers) and manufacturers just misjudge demand. Maybe if they limited to one per person in the parks, they would end up putting some on clearance in a few months and losing money.
Sorry to get deep into the weeds. Just offering another perspective in addition to the consumer perspective.