The owner was concerned that if he locked it up in display cases to prevent breakage and stealing, he would lose many sales. However, if he left it out on display, two things would happen. The owner wanted suggestions on how to sell more and, at the same time, reduce breakage and theft. First off, I think there is nothing wrong with putting expensive or fragile merchandise inside showcases. Doing so shows you have respect for the merchandise and that, yes, it may be fragile, but in its fragility it is beautiful.
Customers tend to respect merchandise that is in locked cases.
When you put it behind glass, it shows you respect it, whereas leaving it exposed may give the opposite impression. It is surprising to me how carelessly some customers handle things they do not own. Until they buy the merchandise, they tend to treat it roughly, without much thought. After the purchase, if they then find a rip or chip, they decry the terrible way others have treated the merchandise. Keeping high-end merchandise in cases can dramatically reduce the shopworn look.