The collier was € 26.400,-- and the bracelet was €24.000,--. I agree with you it was quite eh... substantial, that amount of money. At the other hand the paid prices were more or less in line with the estimation. That means the experts of Christie's, without knowing on beforehand who would buy it, valued it in this range. I don't know how they did the estimation. It is difficult for me to say if it was too much or not. The same amount could have been used for a nice diamond suite, but don't the Oranges already have an awful lot of diamonds?
When looking at the pictures, it is a very beautiful design, there are actually a lot of diamonds in the quite playful setting, surrounded by lots of gemstones. Not my taste but I can see why (then) Princess Máxima fell for it. And also why it had a considerable prize tag. Remove all the coloured gems from the bracelet and you see a pretty decent diamond bracelet in an interesting design and setting. The bracelet alone would already have had a prize tag of € 15.000,--/€ 20.000,-- without the gemstones, I think.