Depends on the retail model, but I guess you guys are correct to a degree. OEMs buy it right away, so they take away all side effects of storage + distribution. Retails, it depends. I would put MicroCenter as an example of a "buyer retailer", so that would put them in line with the OEMs. Amazon (among others) sound like they do outsourcing on some (link you to another store) and also have internal inventory (same case as OEMs here I'd say then). And then the rest, which could use an Intel distributor (if there are any) that takes inventory from Intel to the stores and then back if nothing sells (classic/old retail model).
Prices go up once they leave Intel (much like in AMDs case with Vega/Polaris) and usually favor the middle man in the chain. This includes OEMs, since they can also increase the price of their laptops, I would imagine? But less likely, since they have way more competition among pre-built systems.
Interesting study case, haha.
Cheers!