Probably it was also Alexander's aim further to strengthen his power with the Sacred College, so that he could depend upon a majority to ensure his will in all matters.

But we are at the moment concerned with the matter of the levied tax.
It has been dubbed "an atrocious act of simony;" but the reasoning that so construes it is none so clear.

The cardinals' hats carried with them vast benefices.

These benefices were the property of the Church; they were in the gift and bestowal of the Pope, and in the bestowing of them the Pope levied a proportionate tax.

Setting aside the argument that this tax was not an invention of Alexander's, does such a proceeding really amount to a "sale" of benefices?
A sale presupposes bargaining, a making of terms between two parties, an adjusting of a price to be paid.
There is evidence of no such marketing of these benefices; indeed one cardinal, vowed to poverty, received his hat without the imposition of a tax, another was Cesare's brother-in-law, Amanieu d'Albret, who had been promised the hat a year ago.