I don't think I qualify as "older and wiser" as someone in my mid-30's who is new to fine jewelry. But I'll share anyway
In my opinion, jewelry and other luxury items should be thought of like any other non-essential items (fancy dinners, expensive trips, etc ). You're spending money on something you don't need because you enjoy that thing/experience and it makes you happy. If you want an investment (meaning a financial return on your money), put the money in stocks or index funds.
The amount of money you spend on jewelry each year should be an amount that can be completely "lost" without impacting your short term or long term financial goals (monthly bills, saving for retirement, investing, charitable giving, etc.).
If you want to leave a certain amount of money for your sons after you die, do that without considering the potential resale value of your luxury items. We have no way of knowing what will or won't be valued in the future.
Personally, I'm trying to limit my luxury spending to about 5% of my yearly earnings. My husband makes more than I do, though, so my luxury budget is less than 3% of our combined annual earnings. We could "lose" that amount and be OK.
Re: VCA, I was thinking about a necklace for next year but now I think I'll go for the Socrate BTF ring. It won't retain its value as much as an Alhambra piece would, but as long as I enjoy it that's all that matters. I don't wear any of the necklaces I have and I'm not sure if it's because I don't like wearing necklaces or I just don't have any that I love. But I do wear rings so that seems like a better plan - buy something I know I'll wear!