I wouldn’t mind it, but if Blizzard would implement it it wouldn’t be hovering around those prices.
500 gold is pretty cheap for a race change, even 10K sounds extremely cheap for it. They would likely go with the same formula as they did with azerite pieces, and not put a high end cap on it.
Currently WoW tokens are being used for this, basically, so I doubt Blizzard will change it. You pay 2 tokens for a race change currently, which is more than fine for them.