It's already happening, I know that there are some shops you can shop with your crypto currency, even pundis have lunched their cryptos POS, so it's happening a lot just that it has not attracted mass adaption.
It's possible to buy goods with crypto, but who will do it when the volatility of the market is so high!? It's more beneficial, ofc, to trade cryptocurrency on exchanges cause its price changes momentarily
Question is not when, question is where. It`s already happening, as Bolivar_Tony wrote, some people can buy what
ever they wish, they can pay bills with crypto-currencies.
Next logical question is when will that be available for every person on this world? When that`s happen, we can expect
value of crypto-currencies to grow a lot. It can happen, each of us have some answer on my question, in 5 years or maybe
10 years, it will happen, every person on this plant will be able to buy anything with crypto-currencies.