http://da4hvbumi2ti2izn5hhu3xts3zkdkxvviqdn67zohbqqxyhctylvx7ad.onion/r9k
You can then either outright pay with crypto for stuff (some sites allow it, especially darknet, and there's some physical stores that allow it too), sell it to people in-person to get fiat currency, buy amazon giftcards with crypto (some marketplaces allow this) and just shop there, or buy giftcards and sell them on ebay, or buy stuff or giftcards with crypto; buy goods with them; and then sell the goods on ebay.