Dispuesto a
Could this be translated as 'willingly' - in a non-literal translation of course.
Here's the whole sentence.
Por eso estuvo dispuesto a sacrificar todo lo que tenía.
4 Answers
Yes, I'd translate it as "He was willing to sacrifice all he had" or "He would willingly sacrifice all he had" (you have a typo by the way: "sacrificar")
Unsurprisingly, the cognate "disposed" can also be used most of the time.
A very common English idiom 'to have half a mind to....do something' would apply here. It is much more than just being willing but suggests being 'almost tempted' to do something.
'Because of that, he had half a mind to sacrifice everything he had.'
I would translate it as prepared to or ready to rather than willing to, but that's probably a regional thing. Both of these options sound a little stronger than willing, at least to me.