Both are a huge upgrade from the original AirPods. The 3 are definitely worth the full cost if they fit your ears comfortably. The sound is a decent upgrade over the 2, the ANC is incredible, and they have great battery life.
May as well get the 3 first because you can get them direct from Apple and take advantage of the 14 day return policy if they aren't comfortable, and get a pair of AirPods Pro 2 afterwards.
Sadly for me, these AirPods Pro 3 are so uncomfortable in my ears that I'll be returning them and sticking with my AirPods Pro 2. I'm sad to give up all the upgrades, but at least my ears don't hurt anymore. It's just luck of the draw with the shape of your ears. The first and second generation were perfect for me.