The CIA reports that Greenland has an area of 2.2 million km2 - slightly more than three times the size of Texas - and a population of 56,375 humans. A "flat to gradually sloping icecap covers all but a narrow, mountainous, barren, rocky coast". The ice sheet covers about 80% of the land, and contains about 2.5 million cubic kilometers of ice. If all that ice were to melt, it would increase global sea level by about 7m, or 23 feet.
... for perspective, here's an EPA map of the portions of the US east coast that would be inundated by 1.5m and 3.5m of sea level rise. 3.5m would be reached halfway through a Greenland icesheet collapse. As you can see, the total area isn't that large, but it includes a pretty large fraction of many of the east coast's coastal cities. That would be expensive.