Regarding 1K unit pricing, if there is an increase, I don't expect the 12000K series to be more than $25 expensive in relation with the 11000K series (maybe $35 for the 12900K) and the KF series -$25 vs K series like in the previous gen (although with the VGA increase-even in the entry models- there was an opportunity for Intel to increase the difference to $30)
And the retail pricing in Europe at least, should be close if there is availability, Mindfactory for example was selling the 11000K series even below than 1K pricing (except 11900K/KF which had high demand or should i say low availability, although the last days is priced at 519€ including VAT...) so max 1K unit price difference in worst case scenario imo:
12900K vs 11900K $574-564 vs $539
12700K vs 11700K $424 vs $399
12600K vs 11600K $297 vs $262
This mean that the KF series which is the direct competition for the upcoming Zen3+cache CPUs will be at max:
$549-539 12900KF
$399 12700KF
$262 12600KF
Even if the new 12 core Zen3+ is $599 instead of $549, then for me it will be better value than 12900KF because it will be around 10% faster in both single thread and in multithreading, while the 8 core Zen3+ will be slightly slower in multithreading while costing $50 more in relation with 12700KF (although probably will be 10% faster in single thread) and the 6 core Zen3+ clearly slower than the 12600KF in multithreading but also more than 10% faster in single thread) but still at least 14% more expensive...
The easy choice for gamers will be the new 6 core Zen3+ at $299, for everyone else that is a casual gamer and do mostly work, the better value regarding performance/CPU price will be Intel 12000 series (except 12900K/KF maybe) and regarding the possible price increase, look at it this way: Even if AMD does not increase any price, it will offer you 15% more performance at the same price as Zen3, while Intel will offer probably up to +57% / +38% / +40% more multithreading performance in 12900K/12700K/12600K vs last gen. Also with the above assumptions a $249 5600X does not make sense for a new windows 11 system, 12600KF will be just 5% more expensive while offering at least comparable gaming and single thread performance but will be up to +20% faster in multithreading applications like rendering (performance differences assumed with windows 11 testbed) Although if Alder Lake needs DDR5 to show these performance differences and if you take account that the new Intel chipsets will be more expensive than Z590/B560 etc. while AMD won't need new chipsets, then the tables are turning in favour of AMD regarding performance/platform cost...