Thanks for the alternatives, op, esp the niacin option is one I'll look into. I live in EU and some brands you mention are not available here (and become more expensive when bought from US).

Cheapest black seed oil I can get here is €35/500cl, €52,50/1L. Other option was from India, plus taxes and stuff no cheaper.

Swanson oregano most affordable here. €11/month

NAC I get from eBay/Amazon NL which I can find cheapest.

I looked for (trans)resveratrol/pterostilbene yesterday and can find that quite affordable.

NAD+ is most expensive (with black seed oil) and hard to get here. Earlier mentioned nad/ptero 250/25 and nad/transres 210/70 are €15 a month. Other option is imported Life extension €30/month or Nadh €15/month (but guess that's not a good option).

Different US/EU market sadly. And borders have never been harder.

I'l look into the other brands you mentioned and buying options in EU or imported. Can't evade import taxes/duties anymore as in the good old past :(