The Collaborative International Dictionary of English v.0.48:

Purchaser \Pur"chas*er\, n.
   1. One who purchases; one who acquires property for a
      consideration, generally of money; a buyer; a vendee.
      [1913 Webster]

   2. (Law) One who acquires an estate in lands by his own act
      or agreement, or who takes or obtains an estate by any
      means other than by descent or inheritance.
      [1913 Webster]

WordNet (r) 3.0 (2006):

purchaser
    n 1: a person who buys [syn: buyer, purchaser, emptor,
         vendee]