Do you think studying for ESCA will prepare me even better for CEH?
No, it is the opposite. Studying for the CEH will better prepare you for the ECSA. Studying for the ECSA will not properly prepare you for the CEH.
Is passing the CEH an absolute requirement in order to take the ESCA, I'm wondering if I should just skip the CEH exam and go directly to taking the ECSA exam (after studying for it of course)
No, it is not a requirement to earn the ECSA. The only requirement for ECSA is passing the exam. It is required to have CEH and ECSA to earn LPT though.
(how much is the current ESCA exam fee by the way does anyone know?)
$300 I believe (+$100 application fee if selecting self-study)