I have to admit, the most beautiful pearls I have ever seen were both Mikimoto strands. The AAA akoya are stunning. But an 18 inch 7.5-8mm strand was retailing at $10K USD almost 10 years ago, so would be more now. Three or four years ago I saw a 35 inch multicolor round Tahitian Mikimoto strand. I have never seen pearls so deeply coloured, unblemished, and lustrous. They held colour in full sunlight despite being in the 10 - 12 mm range. But the price tag was $60K (I was wearing them at the time that this was revealed, and I almost fainted). So for that kind of money, you'd expect nothing but the absolute best.
I do wish that pearl grading would become more universal like other gemstones. There could be standards like the 4 C's of diamonds - only for pearls it might be size, luster, surface blemishing, shape, and colour, with different colours being valued more for different types of pearls. So for golden south sea, obviously depth of colour is a factor in price. For WSS, overtone influences value so the colour categories could factor that in. For Tahitians, overtone colour and depth of colour would factor in to the colour grade. Akoya could rate body colour and overtone as well, and there could be standard pearls for matching comparisons like there are for diamonds and coloured stones. I think this would remove a lot of confusion and remove some of the variability that some less scrupulous vendors take advantage of in their grading systems.