AITA because I want something someone else does?

Hello first time post! My grandfather bought a new 4×4 to replace his old one. Apparently my dad wanted to buy the old one and mentioned something about it to me. He’s the kind of guy who will say something but not necessarily mean it. A few months had gone by and I asked my grandfather if he planned on selling it. He told me yes and we made a deal. When my dad found out about the deal all hell broke loose. He called me a snake in the grass a backstabber, saying I was stepping on his dick and trying to steal his deal. He contacted my grandfather about it the situation saying that he called dibs on it because he doesn’t have the money right now. That provoked my grandfather to not want to seek it to either of us. But when I told him what was going on he told me he will sell it to whoever he wants and that he would still sell it to me just because. My dad is very angry about the situation. It was never my intention to try to snake a deal or screw him over but he has been texting shit to me and calling me names. He had even brought my wife into it and starting poking fun at her. I genuinely didn’t know he actually wanted it that bad. I’m supposed to go pick up the 4×4 today but I’m very conflicted about of if I should or shouldn’t. AITA?