To be honest this whole debate is a bit academic. In one situation someone is saying "this thing costs a lot of money and so is a toy for the rich". At the time of the statement it's probably true! You might get into an error by saying "it will always be like that because it's expensive now".
But the issue is that, _even at the time of the statement_, the price has been decreasing over time! It's falsifiable at the time of the statement! You don't need to see the future to dismantle that argument.
Inversely, costs have gone down over time for a long time. You could make the inference that there's a floor, of course, and it's reasonable to do so! But it's hard to disprove the claim that prices will keep on going down.
The former is just on its face wrong based on the current facts, the latter is a judgement call about the future. Totally different beasts, and driven from different things.
Both are assumptions about the future. Neither is falsifiable at the moment of speaking. What would be falsifiable is a statement about the historic rate of change.
I agree that it's generally more likely that a 15-year trend will continue than change. If we're talking about a year, that is. But 5 years? 15 years? 100 years? 1000 years? At some point, the general assumption changes.
But without trend data, I also agree that assuming price stability a better general assumption than assuming a major price drop. Historically, very few things keep getting cheaper. It requires a) large society willing to keep making R&D investments, and b) a technological domain with a lot of possible ways to keep lowering costs.
And what I mostly agree with is the proverb, "It is difficult to make predictions, especially about the future."
But the issue is that, _even at the time of the statement_, the price has been decreasing over time! It's falsifiable at the time of the statement! You don't need to see the future to dismantle that argument.
Inversely, costs have gone down over time for a long time. You could make the inference that there's a floor, of course, and it's reasonable to do so! But it's hard to disprove the claim that prices will keep on going down.
The former is just on its face wrong based on the current facts, the latter is a judgement call about the future. Totally different beasts, and driven from different things.