If you sign an agreement to sell X amount of units within the next Y amount of time, you'll receive a rebate. At least that is how Intel used to do it. The rebate depends on the number of processors you sell, and the actual rebate amounts aren't privy to the public, but the discount can be significant. In the past a $350 CPU the sold moderately would cost an OEM such as Dell almost half that (around $190-$210), while in their (the OEM's) BOM they would charge you the retail price. I imagine an OEM that sells several hundred thousand 12900ks will be able to lower their ASP to around $300 or so. I do NOT expect the 12900k to cost more than $580 (and less with discount resellers like Amazon, the 11900k is $488 right now for example, but the MSRP is actually $550), but we will see. Note all after rebate are ASP (average selling price), so when you multiply that by X amount of units, it adds up pretty quickly. Note that some companies will offer you discounts for buying a large number of units, but Intel, to my knowledge (at least when I worked with them) they don't do that. Perhaps someone here works with Intel currently and can provide insight as to whether they do this.
Please note that my knowledge is pretty out of date. I got out of that game a few decades ago.