This option will let you start a new career with some extra cash, which will be useful to buy better cars and install better upgrades.
It can be found in the Gameplay section of any Extra Options config file.
[Gameplay] ... StartingCash = 0
Need for Speed: Underground
Planned for NFSU Extra Options v184.108.40.2067, along with Starting Style Points.
Need for Speed: Underground 2
Desired amount will be added right at the beginning.
Added in NFSU2 Extra Options v220.127.116.117.
Need for Speed: Most Wanted (2005)
When you finish the prologue races and get to the Rosewood car lot, desired amount will be added into your bank. 30,000 from prologue races and 10,000 from playing Need for Speed: Underground 2 are added seperately from that.
Added in NFSMW Extra Options v18.104.22.1687.
Need for Speed: Carbon
When you break your BMW at lookout point and get to the San Juan car lot, desired amount will be added into your bank. 10,000 from having Collector's Edition is added seperately from that.
Planned for NFSC Extra Options v22.214.171.1247.