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]
(..) in our current situation. - What the hell are you doing? - We must keep moving, doctor. Spock, this thing punched your iliac region. - Time is a critical factor. - That's exactly what I am trying to tell you. Look, I can't take this out. You are gonna die. Okay, if I take it out and can't stop (..)2016 Star Trek Beyond
(..) Captain? We've all heard about the computer simulations and now we were watching for actual simulations but I can't quite believe. You simply haven't taken into account human factor. Human pilot simulations showed that you could have made it back to the airport. No, they don't. (..)2016 Sully
(..) 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