this is obvious enough that you've probably noticed it, but i'll do my due diligence and post it anyway: your example uses completely different words than does the og example you've posted.
your example uses cost(s) as a verb (and conflates the present and past tenses, too).
the og example uses cost(s) as a noun, which must be chosen to agree with the verb that appears later in the sentence.
these are in effect two different words - one a noun, the other a verb - that just happen to look the same. any correlations between them, though, are spurious and should be ignored in the name of proper grammar.
Ron has been teaching various standardized tests for 20 years.
--
Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron