This episode takes place around 1870. Robert E. gets paid $500 for the boiler repairs to the mule. That is the equivalent to $9,589.05 in 2019, but it would've cost significantly more to have the same repairs done in 2019, though.
Dr. Quinn asks Loren why a hat is so expensive. He explains that it is imported from England . This is an inside joke. Jane Seymore is from England and as the star, she is expensive.