That might have been the case at some points in the history of MtG but I don't think recent sets have had positive expected value. For the most part you pay les

That might have been the case at some points in the history of MtG but I don't think recent sets have had positive expected value. For the most part you pay less just getting the cards you need. Or use the opening of packs for actual gaming with the various ways to play with them.