Salary
Average Salary: $10,000
Expected Lifetime Earnings: $40,000
Okay, brace yourself...crossword construction probably won't make you rich. Most constructors work on a freelance basis, on a "per puzzle payment plan," if you will. The best known crossword publisher, the New York Times, pays $200 to $300 a puzzle, and $1,000 if you land a coveted Sunday spot (source). That may sound awesome, but you are still limited by the time it takes to complete a good puzzle (anywhere from a week to a month) and the number of competitors turning in puzzles (source). Ben Tausig, creator of Inkwell Xwords and editor of the American Values Club estimates that a super-efficient crossword writer might make $10,000 in one year, which isn't exactly a living wage.
Another drawback is that you are paid only once; there aren't any royalty checks in the mail, and unless your contract states otherwise, the publisher can resell your puzzles in a book (source). So while it's a great, mind-expanding way to make a bit of scratch on the side, you may want to hold off on the announcement that you're moving to New York to become a crossword writer.
Before you get too down, there are ways to make a little more scratch. You could join an existing group of crossword writers, like CrosSynergy or Inkwell Xwords. They would grant you slightly steadier employment. You could build your own crossword empire, like Matt Gaffney or Brendan Emmett Quigley. Or, if what you really want to do is edit, you might find gainful employment in this field, nurturing other constructorlings in a publishing atmosphere.