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]
(..) every few years... in order to reinvigorate the public's interest. Kind of like the space program. Corporate felt genetic modification would up the wow factor. They're dinosaurs. Wow enough. Not according to our focus groups. The Indominus rex makes us relevant again. The Indominus rex? (..)2015 Jurassic World