but the price of an item as you say is decreasing every day so someone can buy it after it has been out for maybe more than 1 year and the price has gone down in the 30-50% range, so in the long run it won't really affect someone's finances if they buy it based on need and have enough money.
while bitcoin value can go up and down depending on demand but in the long run its value is sure to go up.
so between goods and commodities is very clear.