I've noticed that most OTD programs are quite pricey (think 90,000+), some charging flat rates for students regardless if they are IS or OOS. While researching I did notice that a lot of programs offer opportunities for scholarships (often times merit based not need based).
I found all of these below to be some of the cheapest; however, they are for in-state tuition:
The Ohio State University, $58,359
University of Florida (pre-accreditation), $56,710
University of South Dakota, $52,135