A quick look on the resale market tells me that pave diamond jewelry somehow does not hold value that well.
https://www.fashionphile.com/p/cart...nd-paved-love-wedding-band-ring-49-475-835189
Even the regular diamond Cartier love bracelet does not sell well.
https://www.fashionphile.com/p/cartier-18k-pink-gold-10-diamond-love-bracelet-16-834392
I'm not exactly sure why. I see the full gold jewelry selling for a little better, but not that great to be honest (~15% drop in price from retail). The ones that hold their value better seem to be the ones that are new with tags or barely used.
It may be because diamond jewelry is expensive in the first place, so population of clients willing to pay such a high price are a smaller group. Also, used fine jewelry can have a lot of scratches (depending on the wear and tear) and I think that drops the resale value tremendously.
(Pave diamonds on watches like Cartier and Rolex also do not seem to hold their value as well as watches with no diamonds; but watches are a bit better than fine jewelry in general)
Due to the nature of the 2nd-hand market now, personally I would not sell at the moment for such a huge loss. But that does not guarantee that the price will eventually rise overtime so it's hard to say.

(I also kind of have a policy of not selling my fine jewelry pieces because I don't really expect them to hold value and so when I buy them, I mean to keep them.)