This is really funny though because you are advising people not to sell their bitcoins but you have sold yours for some shopping even when you know you sold at lost due to the price of bitcoin now (though i don't know the price you bought) but it is very wrong to sell when the price of bitcoin is falling just to attend to an immediate need and if i were to be you, i could have considered borrowing to sort out your shopping because i can see you don't have emergency funds in case of situations like this and that is why keeping an emergency funds or making out plans to keep funds for unavoidable events is also important because it will make you not to take regrettable decisions in the future just like the one you took and you are already regretting your actions. It's not like we can't sell bitcoin to attend to an immediate need but let it be done when we have already gotten a big portfolio and when okay with the amount we have accumulated.
He didn't have funds for his urgent needs, so he had to sell bitcoins. So many people say, don't invest more than you can afford to lose. Means you invest in Bitcoin and forget it, and keep funds for your urgent needs so that you don't have to sell Bitcoin in any situation. If you have an emergency fund, you can hold on to the investment in any situation. So we need to plan long term before investing, if you hold for short term then you may not be profitable. Now we don't know whether the person who sold the bitcoins was in profit or loss. Maybe he will regret such act in future. If you don't want to regret in future, then buy again, keep fund for emergency, so that you can hold for long term.