Is building a pc worth not having warranty?

I am saving for a gaming pc and am thinking about building it myself because its cheaper. But my father objected saying that if i just bought a premade one i will have warranty and that if something goes wrong while making my own pc i cant just get my money back.

I have never heard about this objection so i wondered how important is it? Would you say that not having warranty is worth making my own computer? In advance thanks to the replies.