Actually, you're half correct. Greed can be defined as a desire or want for more than one needs, OR, more than one deserves.
So yes, it could be stated that someone who continually works his ass off due to a desire to have more money than is actually needed so he can buy more expensive things and doesn't want that taken away is greedy.
However
If you're going to call that person greedy you also must call the person whose making only $24,000 a year and doesn't have health care, but eats out at resturants twice a week, smokes 2 packs a week, routinely goes to happy hour, and has cable TV greedy for wanting to take money from someone else to pay for his health care that he doesn't "deserve" based off what he does.
If health care is such a necessity, then people should be spending money on it instead of luxuries like going out to a resturant routinely, cable TV, cigerettes or alcohol, video games, or anything of that sort. If its a NECESSITY, then it should be coming before luxuries.
I have sympathy for people that honest to goodness skimp and have almost no luxuries and are actively trying their best to get and hold a job and still can't afford something like shelter, health care, or food. I have significantly less symapthy for people who want to eat their cake and have it too, and wants someone else to pay for that cake.