Oops, forgot that, disregard what I said about TSMC(although still applies to AMD GPUs)
Certainly wouldn't put it past Samsung to increase prices over time though, would be very costly for Nvidia to switch to die production to from Samsung 8nm to TSMC 7nm.
You have a point about some (often cheaper) models not coming into stock, I remember trying to get a basic Asus RTX 3070, but only the more expensive models were ever stock in Jan/February.
The way those kind of contracts are usually negotiated the bulk of the product cycle would be at a fixed cost (the flip side being a minimum order quantity that would have to be covered even if demand wasn't there). There would be a certain point where the price could increase but they can't normally just turn around and say from tomorrow we are going to charge you double, etc.
Given the MSRP and the way AIBs have manipulated availability (and in some cases sold directly outside retail to scalpers or miners, etc.) I have my doubts that the majority of blame for prices comes from what nVidia charge AIBs but I could be wrong.