Lark is correct, it is dynamic. For any given flight, there are usally 4-6 different prices depnding on seat (regular E+, exit row front/back, aisle/window/center.) I've seen the exact sam flight on different days have different prces, I assume it is based on demand. Not sure if the process is variable on a flight based on predicted demands, or if the price changes along the booking curve variable over time as demand shifts.

I'd guess the (3) variables are 1) length of haul, 2) actual seat chosen, and 3) demand.