Complex sentence: He was later sold to Milton H. Sanford for $10,000 in a package deal along with two mares and he did quite well but it wasn't until he was sold again to Daniel Swigert that he hit his stride.
Split into simpler sentences: He was later sold to Milton H. Sanford for $10,000 along with two mares. He later did quite well but it wasn't until he was sold again to Daniel Swigert that he hit his stride.