Complex sentence: If so, a 250 page book would start at $18,000; and with no draft or similar attempt at writing the text (extensive sketches), $28,000 is more likely starting price.
Split into simpler sentences: If so, a 250 page book would start at $18,000. With no draft or no similar attempt at writing the text (extensive sketches), $28,000 is a more likely starting price.