Yup, nothing wrong with looking for a used one. Especially if the OP isn’t up to repairing the one he has himself.
That said, almost all the used ones are like 50+ years old, and the factory welds were pretty sketchy on some of them. So any used replacement should be fully inspected for cracked welds, rust, damage, and being straight. Wouldn’t be too hard to unintentionally replace one bad K frame needing repair with another one that needs also repair if you’re not careful.