yes,they do cost too much but it's just a one time thing and it has a lot more capabilities that text books don't have and most importantly, they are good for the nature cause they don't have wood in them
Whether a student can learn more depends on the student. Students can goof off and not learn anything with features of a computer. Features include internet, games, and applications. With a textbook, they can't do any of that stuff. It is also not a 1 time payment if the computers have technical difficulties or they are stolen. If that happens, it costs miuch more to replace a computer than a textbook.
you can limit the computers to just be about the lessons and be sure that if the students want to goof off, they would goof off any way and it's not related to the things that they learn from, they goof off because of the methods
and about the payment, i have gotta say that reparation is not expensive (actually it can be if the damage is too much and is done to the hardware but usually they are just software failure that don't cost much) and if you guard it good, it can't be stolen