I do not think one should change the rules of a certain product release afterwards. The price for RW cards and RW card packs reflects (reflected I guess) the agreed price of 5 USD per pack. As pointed out, if you can buy in DEC the price would right now be 2,7 USD or whatever. The result would not be a sustained rise in DEC IMO; people would sell their SPS to capture this arbitrage in the short term and then the scarcity rule for RW cards would be destroyed. As for the price for RW, I do not think it is unreasonable with a higher price tag than CL.

Furthermore, I do not understand why there should be a need for this discount talk already after only a few weeks of sales? This is supposed to be something sold over a period of time, no?

Another thing. If DEC is under the soft peg of 1000 DEC = 1 USD envisioned by the company it is because the market determines the price to be so. The reasons for that could also be a reaction to the current reward structure, as well as the overhanging amount of CL packs. There are a boatload of cards being minted daily as rewards, many millions of CL packs yet to be sold (thereby increasing the "collateral" part of the DEC universe) and so on.

Slightly off-topic here, but of importance. I think that the change to the rewards from the old system to the Ranked Rewards structure was 100% awesome, without hesitation. However, this has probably led to unintended consequences with regards to the distribution of cards/potions/SPS as rewards that has further lowered the value of the tokens. This might be partially corrected by the other SPS.DAO proposal on vote (card level discussion), but I think the increase in payouts has been massive, especially for Bronze and to a certain extent Silver.

So TLDR; Fix the underlying issues with the current dilution of DEC instead of trying to intervene here and there.