Which preposition to use with purchasings

OF Occurrences 9%

IN THE PURCHASING OF LAMB FOR THE TABLE, there are certain signs by which the experienced judgment is able to form an accurate opinion whether the animal has been lately slaughtered, and whether the joints possess that condition of fibre indicative of good and wholesome meat.

by Occurrences 1%

This purchasing by Lanpher and Tweezy of the Dale mortgage was the eminently safe and lawful plan of Jakey Pooley.

for Occurrences 1%

To lessen the chances of disagreements in trading and to keep some control of prices, Cook ordered that only one person should conduct the purchasing for the ship, and as Banks had shown aptitude in dealing with the natives, he was appointed.

Which preposition to use with  purchasings