How do you see the theme of greed in Treasure Island?

The treasure in Treasure Island is initially a concept only, represented by a map. The map itself is like a portal to gold’s power, and, like the ring in Lord of the Rings, Captain Flint’s map signifies a glittering objective, its particular allure subjective to its beholder. Jim sees it as an invitation to wild adventure and romance, as he’s been hitherto grounded at an inn with his mother. To Jim’s advisors, Dr. Livesey and Squire Trelawney, the map touches off an exploratory zeal: of course they’re driven to mount an expedition in an attempt to recover the sea chest.
To a lesser extent to that of the pirates, greed is an influencial force underscoring Jim’s and the upright adults’ visions. Jim realizes on the island that he’s been susceptible to flattery, by the “abominable old rogue” Silver, for example. He and the Squire and the Doctor are like the marks that a con man targets, exploited for their weakness.
And to Long John Silver and his motley crew, Flint’s treasure is one more conquest along the spectrum of life-or-death power struggle to massive pay-off that’s pretty much intrinsic to the whole pirating enterprise. As Silver says, “Lambs wasn’t the word for Flint’s old buccaneers.”

Here is is about gentlemen of fortune (Silver’s euphemism for pirates), they lives rough, and they risk swinging, they they eat and drink like fighting cocks, and when a cruise is done, why, it’s hundreds of pounds instead of hundreds of farthings in his pockets.

When splinter groups of mutinous crewmen plot, drunkenly betray and kill each other, it’s because of the loot at the heart of it. Silver is older, farsighted, and accustomed to treatury. But the actual material goal is less the point than what people are willing to do, or do to others, to aquire it.