I live in a development where our mailboxes are banked outside one of the floors in my building. My mailbox is one brass-looking compartment of around a dozen. I have no options.
When I did have my own mailbox, I wondered about getting a fancier one. However, sometimes the mailbox takes away from the house. Also, those things get hit by cars sometimes. Maybe one with more presence would be more visible, and less likely to be knocked down.
Anyway, to answer your question, to me, a nice mailbox is a practical mailbox. So, having a nice mailbox is very important to me, but not in the way that you are implying.
I don’t know. Maybe this is a case of the grass is greener on the other side. What if your neighbor loathed his or her mailbox, but was forced into purchasing it just for show?
Maybe the reason why your neighbor has a nice mailbox won’t make you question yours any less, but yea, are there not more pressing things to spend $10k+ on?