I checked the prices for 64GB DDR5. There's some variance based on brand/model but the average and trend seems more or less right. Did you happen to notice that it is about prices in the EU?
Their price history does not reflect this at all, so I'm not trusting their values one bit.
At best, they changed their complete history to reflect a different product (or basket of products), and while the 16GB-DDR5 category is closer to accurate now, the 32GB is now too high: 32GB of DDR5-6000 can be had for 400ish in the Netherlands (or elsewhere in Europe).
https://pcpartpicker.com/trends/price/memory/ may be more interesting to US users.