No, air in the bottle after opening it still affects the wine, even if you put the cork back on. That's why they use argon.

And who wants vendor lock-in with "proprietary argon gas capsules".

I assume they have a patent on it so it's unlikely that we will see any generic equivalent for a while.

Maybe, but I doubt it - machines using inert gas to preserve and pour wine have been around since Enomatic in the '70s. The only thing new here is the cheap price point.

Yeah, it only makes sense for bottles costing upwards of 100$

Or very limited vintages. I have a few bottles that were $35-50 when bought, but only had 150-300 cases made. No way to get another of that same kind and same year...

Which makes the bottle now worth probably a few hundred at least.

Probably not. There are many small wine producers that will only produce a few hundred cases of wine each year. Despite being scarce, this wine won't be specifically valuable unless it's good or otherwise unique, because it's only a very small part of a very large market. The $35 wine will still cost $35. You won't be able to buy it any more, but there'll be little interest from others.