Even now, people are fascinated and obsessed by the beauty of pearls. The word translated as merchant here is the word for a wholesaler of pearls, one who buys pearls from the pearl divers and resells them. But the man in parable seems to be concerned not so much with what he can get out of it by re-selling it, as by the worth of the pearl itself. He is so obsessed by its beauty and perfection, that he must have it at all costs. He is like an obsessive collector.
People collect all kinds of things.
Some people would give an arm and a leg to own a rare stamp, or a 1930 Australian penny, or a particular piece of exquisite 18 th century furniture. Because it IS a pearl of great price. Now in one way it is absolutely free. The bible teaches that salvation is a free gift of God, it is not earned but comes only by faith in Jesus who died for our sins and rose again. But although it costs you nothing, yet in another sense it costs you everything.