I really don't think the price of the CPUs themselves is the hindrance here.
Consider, cheapest 7600X / 7700X 32GB DDR5-5600 build I can do at Microcenter:
Assumption : You've got a case, PSU, KB / mouse, Wifi Card/wired connection, OS license, CPU cooler, and drives
ASRock X670E PG Lightning AMD AM5 : $259 (note, this just dopped $10 in price)
Corsair Vengeance 32GB (2 x 16GB) DDR5-5600 C36 : $157
7600X : $299
$20 discount on MB/CPU combo : -$20
Total : $695
Sub 7700X @$399:
Total : $795
So, lets say AMD lopped off $50 on the CPU price. That would save you 7% on the 7600X build, and 6.2% on the 7700X build.
Also keep in mind, with the build above, you're not going to see the kind of numbers in the reviews with it.
You need faster memory, and a better cooler than a typical Zen 2/Zen 3 user has. Assuming this mobo can actually hit DDR5-6000, you need to spend about $90 more on RAM and $120 on an AIO that can handle the heat. That brings the totals up to $815 for 7600X build and $915 for 7700X build. This still might not be enough, this is the cheapest ASRock mobo available, no idea how good it is but ASRock doesn't have a good rep right now on low and midrange boards, and most of the cheap boards you're *lucky* if you can hit DDR5-6000 (at least on Alder Lake).
None of these boards seem to have Wifi either, whereas Z690 / Z790 chipsets have a built in AX211 wifi 6E controller - so many of the boards have this for just $10-$20 more. For example, the MSI Z690-A Pro Wifi DDR5 is $239 from MC (no markdown). The Same Z690-A Pro DDR5 without Wifi is only $179 (marked down from $209).
i.e. if you have to buy a Wifi card, that's another $50 or so.
At these prices, lowering the CPU cost $50 - helps - but not much.