The Collaborative International Dictionary of English v.0.48:

Purchasable \Pur"chas*a*ble\, a.
   Capable of being bought, purchased, or obtained for a
   consideration; hence, venal; corrupt.
   [1913 Webster]

         Money being the counterbalance to all things
         purchasable by it, as much as you take off from the
         value of money, so much you add to the price of things
         exchanged.                               --Locke.
   [1913 Webster]

WordNet (r) 3.0 (2006):

purchasable
    adj 1: capable of being corrupted; "corruptible judges";
           "dishonest politicians"; "a purchasable senator"; "a
           venal police officer" [syn: corruptible, bribable,
           dishonest, purchasable, venal]
    2: available for purchase; "purchasable goods"; "many houses in
       the area are for sale" [syn: purchasable, for sale]

Moby Thesaurus II by Grady Ward, 1.0:

22 Moby Thesaurus words for "purchasable":
   approachable, available, bribable, buyable, corrupt, corruptible,
   fixable, hireling, marketable, mercenary, obtainable,
   on the market, on the pad, on the take, salable, slippery,
   to be had, treacherous, tricky, undependable, unreliable, venal