Hi there,
I got my vaccines at the medical appointment in Guayaquil, as they know what to fill and what to give you already. You might cut prices if you get the flu vaccine in a Centro de Salud, which is free and at the Medical is about $20.00. I still don't know if it was better or not as I haven't shown or used my vaccines report yet, but as I read in other places it was best to get them before you arrive to the US as it might cost you way more.