Buying 1 BTC was realistic for many people before the first 3 halvings. Now that is no longer the case.
It's still realistic and the same questions will rise again when we're gone far and the prices are too much already.
- Why would people invest loads of money in BTC after the halving and not before?
That is because they like more confirmation that the price have already increased than to wait patiently before it goes up. We're humans and only a few believes on what we're telling to buy now and wait until the price goes up, that's their approach and strategy that's so wrong but we can't blame them.
- What is a good price range for an air gapped wallet, for someone who only manages 0.3 BTC?
I take security very seriously. I'm in doubt between coldcard and Ngrave. Both are not very cheap. Ngrave will be over 500 bucks, which I think is a lot for someone who only manages a 13k portfolio. On the other hand, the value may increase and I want to take 0 risks losing my portfolio
An old desktop or laptop if you have will be enough. The important thing is to download the official wallet of Electrum from its official website because too many clones and fake out there.