Their prices can really get prohibitive fast. How big is your list?
Wild and probably hard idea, but depending on number of list signups, you could always go manual first to really get a feel for the process.
Google sheet a schedule for 4-5 marketing drips, schedule them out. Say that you're manually sending these for a closer feel and love to hear back from people, treat the whole thing like a private newsletter to welcome them into the fold.
-Signed, Somebody that probably needs more therapy 😅