>They will have been extra cautious this time, but from the above, the answers _could_ be "about 10%" and "almost one year, taking way more effort than building a new one does".
not sure if 1 year is actually correct. From what i've read SpaceX originally was not planning on reflying this core, as it was their best flight tested article and they did not want to risk loosing the value of having it for future reference, but then a later landing with another core was a bit rougher than anticipated and they did not feel comfortable with the margins of reusing that core. So part of that year they were waffling on if they wanted to fly this core or not.
not sure if 1 year is actually correct. From what i've read SpaceX originally was not planning on reflying this core, as it was their best flight tested article and they did not want to risk loosing the value of having it for future reference, but then a later landing with another core was a bit rougher than anticipated and they did not feel comfortable with the margins of reusing that core. So part of that year they were waffling on if they wanted to fly this core or not.