Looking in more detail, $5k was for TAMU Laredo (International). 99% of students were in-state, and in-state tuition was $8k. ~90% of students were earning degree online via distance education and most likely living at home, so expenses were likely not far beyond the $8k tuition + fees + books for this group. 99% received grant/scholarship aid with an average grant of $11k. With most paying not much above $8k + fees + books and average aid of ~$11k, resulting net cost was low. The vast majority of students were in the federal database (mostly federal aid recipients), and for this vast majority, the average net cost was under $4k.
In contrast, the flagship at College Station had by far the highest reported average cost for this income range among the TAMU system at $26k. In-state tuition for college station was $13k. Rather than tuition, I expect the primary difference is a tremendously larger portion of students live on campus and have the extra ~$20k/year sticker for room & board. They also have a small minority out-of-state students, with >$60k sticker price.