France vs Spain semifinal tickets. Best way to get tickets this late, and is now the right time to buy?

I've been watching this sport my whole life and never made it to a big game in person. Really want to make this one happen.

Been checking FIFA's ticketing marketplace and SeatGeek, prices are all over the place and I can't tell what's actually a good move.

Trying to figure out:

• Is FIFA's official resale marketplace the best place to get tickets?
• Is now the right time to buy, or should I wait closer to kickoff?
• Do SeatGeek/StubHub prices usually drop as kickoff approaches or spike for a match like this?
• Any platforms I'm missing that are worth checking?
• Is buying day-of at the stadium a real option for a game this big?

Not trying to sit pitchside, just want to be in the building for the game. Anyone who's actually bought last-minute tickets, what worked for you?

Thanks in advance.