It`s your decision, and it fully depends on the buyer. In my case, I bought a domain to build a website, but this will take time, so in the meantime, I decided to offer my domain for sale, and guess what! I got a 4-digit offer on my domain, and yet, I decided not to sell because it is worth more, and I would probably need it ( unless a tempting offer comes ).
The point is, it all started because I saw needed it, and if you think: That`s not an investment, you just bought it for another purpose," you`re wrong, as long as you spent money, it`s already an investment.
It all depends on you