What is the Rav’s opinion regarding one who brings seforim to sell to a yeshiva, and the bachurim look at the seforim, which they may or may not have intention of buying? How long may one look at a sefer for free? Or one who goes to a seforim store and looks at seforim that he may or may not intend to buy? How long can one look at them for free? Does it make a difference if one intends that maybe he will buy the sefer, versus one who knows certainly that he will not buy it?
It depends on what the owner allows, and I can’t give a amount of time, because it depends on what he allows, if he allows it at all. He surely wouldn’t mind if someone looks at a sefer shortly if there is a chance that he wil buy it, but the amouont will depend on the individual.