Due to the blessing of Risk or some kind fate, you are exceptionally lucky. Each level, you have 5 Luck Points, which may be used as a thief's luck points. If your class already grants luck points, add these to your total. Unused luck points are discarded with each new level, and may not be saved. This talent may be purchased multiple times, each time adding 5 luck points to the total. However, each purchase after the first adds 15 to the cost; so the second purchase will cost 30 BP, the third 45, the fourth (and final) 60.
Notes: At that point, you've got 20 Luck points per level, sure... but you've also put 150 BP into luck points and only luck points.