The Ohr Hachaim Hakadosh [23/19] says that Avraham didn't acquire the שדה עפרון with a קנין כסף but with a קנין חזרה - see there.
If so - then BY GOLLY how does the gemara at the begnning of Kiddushin learn from this transaction that a woman is נקנית בכסף??
And why would parents name their kid after a pencil???
And why would parents name their kid after a pencil???