Going to your local Salvation Army or Goodwill store is also an option. I bought an old game that had a few of the wood tiles missing for $1.50 and I was only missing 2 A's so now I have extra's.
You can buy replacement scrabble letters from www.scrabblespares.com
Spare letters for Scrabble are not sold separately, and to get more letters, it is advisable to buy a new full-fledged Scrabble set. Hasbro Inc. Is the world's largest game company. Die-hard aficionados of the game would tell you that it is the wisest investment to make, as there is no improved means to increase your vocabulary than solving crossword puzzles and playing Scrabble. Scrabble sets are available at all leading toy-stores and most departmental stores all over the world. Incidentally, the five vowels (A, E, I, O and you), which are practically used in almost every word in the English language, alone make up 42 per cent of the total number of letter tiles in a standard Scrabble set, and they account for 42 points out of the total number of points at stake. Hasbro Inc. Is now the parent company of several top game companies, including the Springfield, Massachusetts-based Milton Bradley Company (which was established in 1860). The Milton Bradley Company, the leading American game company, in turn purchased Selchow and Righter, the makers of Scrabble, in 1987. Besides the original Scrabble, some costlier versions which are available in the international market are the Scrabble Deluxe Edition, the Scrabble Deluxe Travel Edition and the Scrabble Junior.