Goods and services will never be priced in BTC because BTC fluctuates by the hour and will probably continue to do so for the foreseeable future. The only way I can see this happening is if you literally eliminate all other currencies, including other cryptocurrencies, because there will always be currencies competing with BTC (and not without good reason).

Classic example of buying a good using BTC: say it costs 100 satoshis. By the time I click and purchase, and by the time the BTC arrives at the seller's address, the value may have changed for the better (BTC price goes down - hence I paid "less") or for the worse (BTC price goes up - hence I paid "more"). For the most extreme example, imagine how people that bought a pizza with Bitcoin when it was worth 5$ feel right now. A 15$ pizza in 2009 or whatever is worth ~150K USD now.