Congrats!!
If you have the cash, why not.. ?!!! It's a keepsake, and something to hand down within the family.... My sister has kids and she had gifts from her other half..
I really like Jessica Lotz - she does a lot of keepsake type jewellery - some of it is is mid price, but if you go for gold it can be pricey - but her pieces can be handed down to generations...
https://jessicadelotz.co.uk/ She does a lot of bespoke - her work is quite unusual, so not for everyone, but I really like her wax seal charms which come in a range of sizes. I had one from my Sis for my 40th and I cherish it ;o)
Good luck and don't feel guilty for wanting a pressie!!!