Bear with me, Ryzenoids.
www.amazon.com.au/AMD-Ryzen-7-5800X/dp/B0815XFSGK - Ryzen 5800X @ $380.32
www.amazon.com.au/promotion/psp/A4R68XV5FMLHQ - other eligible items @ 6% off
The AMD Ryzen 7 5800X is an AM4 socket 8 core/16 thread CPU which runs at 3.8Ghz with 4.7GHz boost, 36MB cache and 105w draw. To some extent, it's reputation as a high performance thermal oven sees many preferring the 5700X (which runs marginally slower but much cooler), the 58003DX (worse mutli-thread performance but great for gamers or other single-threaders due to huge cache) and the 5900x or 5950x (superior multi-thread performance but expensive), but it occupies a healthy place in the Enthusiast-class middle ground and is a great value for money drop-in upgrade for many existing Zen, Zen+ or Zen2 owners or those looking for bang for buck Zen3 systems whilst early adopter pricing abates on the new AM5 platform.
Amazon US are currently running a "Buy 2, get 6% off" promo at www.amazon.com.au/promotion/psp/A2GQU4VR43P0HM, featuring a wide range of items, amongst them - the Ryzen 7 5800X - with a delivered price for a single unit of $380.32 after discount. To participate, you need to add one of the other eligible items, but even so, it's possible to land the 5800X plus one other trinket from $386.32 delivered in total. Whilst you can't sort the above list by price, you can you the filter at the bottom left of the page to only list items below $10, $20 or any other amount. The 5800X is also listed as eligible for the current AMD "Free Uncharted game promo" as shown as www.amd.com/en/gaming/ryzen-uncharted-bundle, but I can't personally verify so don't brand me with a flaming CPU if I'm wrong…
Cheapest eligible items (prices shown before 6% discount) I could find which didn't attract additional shipping charges currently include;
Paint defect remover for $6.37 - https://www.amazon.com.au/dp/B00F7OR9QC.
French phrases for kids book $7.94 - https://www.amazon.com.au/dp/0486803619
Botanical Affirmations Colouring Book $8.19 - https://www.amazon.com.au/dp/B089TRW7BZ
Pete the Cat book - $8.84 - https://www.amazon.com.au/dp/0062675214
Command Universal Picture Hanger - $13.85 https://www.amazon.com.au/gp/product/B00404YRY2
Pentel EnerGel Alloy RT Gel Pen - $14.49 https://www.amazon.com.au/gp/product/B0026ZPWZA
There's hundreds of other items to choose from if you want something genuinely useful, rather than just something that will see you spend less overall after the 6% discount. The items listed above didn't attract any shipping fee for me, but beware that some other items not listed, do. Delivery for me to Sydney was shown as November 1.
As always with Amazon, it could be available for a long time or a little, and you may have to tweak the "Sold by" filter if doesn't default to "Sold By Amazon US" for you. Personally, I'm waiting for a deal on the slightly lesser 5700X, but I believe this is the first time the faster 5800X has ever been listed under $400, so hopefully it suits someone's needs. Just beware, you will need to purchase or repurpose your own CPU cooler. And for the RGB'ers amongst you - it's available in any colour you like, so long as it's ceramic grey…
Would this be a reasonable upgrade from a 7700k for primarily gaming?