I recently just came across the same issue and I’m shocked it still is not regularly supplied after all this time. I am not sure what you all ended up doing, but I ended up contacting Creality support and they were able to provide the part at only $5.91. However it came with $30 flat shipping, so unfortunately kind of had the same issue with paying $36 for a $6 part. What ended up making most sense to me as a solution was to buy a couple so I could spread out the cost of shipping, meaning I have a few extra. If you are in the US that should limit shipping cost and shipping time. I had to wait about a month to get mine, but they say that was because of the Chinese New Year. As for outside the US, looks like the eBay international shipping rate is around $15-20, which is more reasonable than buying from Australia, but I wonder if you have been able to contact Creality directly?
You can check eBay for “Creality Ender 3 V3 Plus Replacement Tool Head Wiring Cable (SKU 3103110630)”. They are currently listed at $16 plus shipping, as I am not trying to make a huge profit and hope this can help people who are in the same situation I was. If this works out I (or someone else) could potentially buy more at once to limit the shipping cost per item and offer them at a reasonable price? I am wondering why no one else has done this, but could not imagine against any restrictions since Creality is still getting their $5.91 and we are just saving shipping costs, but let me know if anyone thinks otherwise! It just seems to me like such a supply issue should not be happening!
I hope this helps!