Cost was the 'decisive/deciding/determining factor' in their decision. [=the most important reason for their decision]
The 'deciding factor' was cost. [=the decision was based on cost; the least expensive option was chosen]
Costs increased/decreased by a 'factor' of 10. [=costs were 10 times higher/lower than they had been]
(..) Lobotomies tend to do that. Well, think of the benefits in terms of design time, maintenance, costs. Not to mention the Dr. Ford factor. The guy's gonna chase his demons right over the deep end. I mean, no one respects him more than me, (..)2016 TvShow: Westworld Title: The Original Season: 1 Episode 1