Card prices are actually not that clear either, take a look at the set value for Rebellion Set:
The long downtrend seems to be broken additionally this is going to be a very rare set. 62% of the set is already burned and I would not be surprised if this will reach 80% burned before it is gone at the end of this year. With under a million packs sold this set is tiny:
Compare this to the Chaos legion set where there are over 2 million packs circulating and 10.5 million open!
Even with such an overhang of Chaos Legion cards and packs the value of many key Chaos Legion cards doubled from the bottom a few months ago... And there is very little card liquidity at low prices so even 100 new players that decide to buy maxed out cards can cause Chaos Legion value to quadruple.