We haven't had enough time for there to be many people who want sleeves and weren't around to get them when they were easy. The extreme rarity does indeed make the equips significant but the low chance makes them again a small proportion of the pack value.
There is value in the pack because it costs a significant chunk of gold to buy in the first place. Rarity is not adding value to the pack just moving it around between the contents. Quality of effect can affect value of course especially once they go 'out of print'.
Yes your right, the sleeve is a factor and I did not deny that. As I said the legendary equip is part of what drives the value. The way you wrote it made it seem that you believe it is the only factor, which is why I said it isnt.
Furthermore, the low chance still makes them a significant part of the EV. For instance:
- Based on the gathered community statistics (I know its not statistical signficant enough to draw a a valid conclusion but it does give some indication)
Suppose both legendary equips have a drop chance of ~2% and lets say they both would sell for around 2,000p atm (which is reasonable and not too much more than while they were in the store). In 100 packs you would statistically get 4 equips which would have a value of 8,000p. 8,000p / 100 = 80p.
The two equipment would essentially already resemble 80p of the EV of an pack. I would say that it is quite a significant part of the value.
When it comes to the value, in the end the deciding factor is supply and demand. Many factors, such as the price of the pack that you mentioned, simply affect the supply and demand.
While rarity can shift the value around during the time that they are in the store, it does not after they rotate out. And while they are in the store, the value can only shift around when there are enough valuable things where a decrease of the drop rate of other content actually increases the value of the item.
Right now, from what I observed, besides the legendary equipment in the Oni pack the supply out weight the demand so strongly that basically most cards were sold at or close to price floor with many listings. In order to create value for these cards, the drop rate would need to be significantly reduced to the point where people complain again about too many uncommon equips etc. Otherwise, in my personal opinion I do not think the value of the pack would shift. Instead I believe that the supply of legendary equips would simply increase and the overall value decrease.
Overall, I think its a good thing that they are rare and chase items with high value. They already reduced the buying price which greatly reduced the costs to get the set. They should keep the rarity and have parts of them valuable as an incentive to buy or farm them.