Correct me if I'm wrong, but buying stuff from the darknet markets isn't really illegal if you're purchasing stuff that's legal.. right? (assuming that CBD is actually legal in your country; did a quick Google search and apparently European countries has different legalities when talking about CBD).
No that's legal on the dark web, what is illegal is to import illegal products. However, It's legal in my country, but can't imagine me purchasing on the darknet, too many risk to receive weird thing like grass, or dried chives.
There are even shops that pop out in streets and websites too but as you can guess, no bitcoin option
You might get some shady dealers in this forum too. But please follow local rules and regulations regarding the same. I know the all anti-mainstream attitude seems "cool" but it is not worth it because of the consequences.
If you live somewhere where the purchase of such products are legal then just use fiat, if you dont which I assume is the case because you made this thread, try to get in contact with someone on this forum who is such a Cannabis-legal country and see if they can help you out. I dont know if airport checking for it done or not, if not it might be the best method to procure some.
However I do not like suggesting someone to take such products, so please use them for proper indications and not for recreation.
The forum is probably one of the last place to go for. There is no recreation possible with CBD