This hypothetical scenario is muddled. OP is lamenting an investment decision (sell BTC, buy computer). It's irrelevant that he/she might have had extra funds (the second $2,000 of bitcoin in your example) that weren't part of that investment decision. OP probably owns other assets as well (car, stocks, patio furniture, etc.). They weren't part of the investment, either. They're irrelevant to this analysis.

Saying the computer was free is misunderstanding what "free" means. If the computer were free, he/she would have paid $0 for it and would still have the bitcoin.

Of course you're right that I am misusing the word "free." But, I understood OP to be criticizing the deflationary nature of Bitcoin rather than lamenting a personal decision to spend his/her own bitcoin holdings. My point was just that it isn't a bad thing for your money to triple in value.

Interesting example. Bitcoin as an example of increased purchasing power facilitated by an increase in productivity and value generation of the entire (global) economy. Thus, a more prosperous ecosystem makes each individual who shares its "currency" wealthier over time - a distribution of the time savings / value generation to all participants.