Determine how often you plan on freeze drying food. Purchasing a new unit is costly; a basic multi use bench-top freeze drier starts at about $12,000. It processes a little over two pounds of food during one session. A bigger unit that processes about 20 pounds starts at around $16,000. You may be able to pick up a used model for less money, but it could take a little while before you find one in the size you want. For example, a used freeze dryer with a 1.59 gallon tray capacity starts at about $4,000.