The intent of this measure is to provide added assistance to students. It's not intended to cover the full cost of education or the full cost of textbooks. It's intended to provide some assistance. As indicated, it is calculated as $65 per month, for those who qualify for the education tax credit.
There's an example in the budget documents of an individual spending eight months of the year at a Canadian university, claiming $3,200 in education amounts and $4,000 in tuition, for a tax savings of $1,116—and increasing the amount of that assistance by $80.60 as a result of this new textbook tax credit.