Well Raven has already 360k, and more than 11 years old, at this point I see no reason to put money in it, drive it till it dies. My old 1997 automatic civic tranny had the same issue and I changed the tranny fluid and nothing changed.
That didn't stop me from doing long distance (500 Km) every month with it and the tranny never went down. instead of investing money in a probably rusted 11 year old mazda 3, just buy a membership with CAA or something, just incase it breaks down while your driving