So I have family that just moved to Spain. My question is would they be able to send me a box of Cubans without them being confiscated? They live in Barcelona so I'm sure there would be some good cigar shops in that area.

Only a few at a time. I wouldn't try a whole box. Try 3 to 4 first.

ETA: Look up Habanos S.A to find an authorized dealer near them to buy from.

This right there. It's the only way to make sure you get the real deal.

Cubans are scarce in most/all of Europe right now. Was in a few different Habanos shops in Germany and France recently and the selection is nil currently. Prices are also 2-3x a year ago.  You'll have a hard time getting a whole box of real sticks most likely even before customs confiscates them.

If they have to go through Miami expect them to get confiscated.   Right now that port is hot on confiscation.   Other ports are somewhat reliable in getting through.  Reminder.  If you have global entry you can lose it by having goods shipped to you that are banned.    

Spain used to be cheap and reliable for Cubans.  Now, with global pricing, it’s all the same.   Habanos stores are the gold standard but unless you like to pay $500 for a box of mid level Cuban cigars, you aren’t buying Cubans.   Montecristo #2 are around $700 iirc right now.  Cohiba and Trinidad are insanely expensive at this point.  

Minimum is around $20 a stick for smaller ones and plenty of other non Cuban cigars are decent at that price point.  Personal packages are confiscated less but Miami customs is a terror as mentioned.  

Unless there is a specific stick you want I would skip the drama and just buy Davidoffs, Opus or Liga Privadas and call it good.

I'd can this idea and only buy from a reputable vendor with a money back guarantee (even if confiscated).

This. I just discovered the grey market websites that ship to the US, and there are quite a few that have money back guarantees. On Reddit, /r/cubancigars has a post in their sidebar about reputable grey market sites. Apparently takes like 6 weeks for them to confirm the confiscation and refund you, but you still don't have much actual risk apart from losing global entry.

Overall what others have posted is pretty much true though. Having your family send stuff individually doesn't have the money back guarantee if they get nicked in customs. And prices have gone nuts. And quality control isn't always 100% despite the prices you're paying.

Having tried my first CCs recently, and now finding those grey market sites, I'm still tempted to buy some of the more "affordable" options to have around for small personal special occasions. "Affordable" being like $10/stick for tiny H. Uppmann Half Coronas. But besides that, I'll stick to NC's for the vast bulk of my smoking, because high end NC's are every bit as satisfying, for similar or less money, and there's no worries about confiscation.

Just......... Why?

When Castro took over, the growers took their seed to new locations around the world that are now producing sticks that are as good and better than the legendary cuban.