Secret Menu purchases:

Blaster damage upgrade	6 Precursor Orbs After Act 1-9
Dark Jak invisibility	25 Precursor Orbs After Act 3-11
Improved Blaster	4 Precursor Orbs After Act 1-17
Improved Peace Maker	4 Precursor Orbs After Act 2-19
Improved Scatter Gun	4 Precursor Orbs After Act 1-17
Increased Vulcan Fury	4 Precursor Orbs After Act 1-24
Invulnerability	100 Precursor Orbs After Act 3-11
Jak 3 model viewer	2 Precursor Orbs After Act 3-11
Jak and Daxter viewer	2 Precursor Orbs After Act 1-24
Jak II model viewer	2 Precursor Orbs After Act 2-25
Mega scrap book	2 Precursor Orbs After Act 3-11
Better Peace Maker radius	6 Precursor Orbs After Act 2-19
Gun courses	6 Precursor Orbs After Act 2-12
Faster Scatter Gun	6 Precursor Orbs After Act 1-9
Scrap book	2 Precursor Orbs After Act 1-24
Unlimited ammo	50 Precursor Orbs After Act 3-11
Unlimited Dark Jak	50 Precursor Orbs After Act 3-11
Unlimited Light Jak	50 Precursor Orbs After Act 3-11
Unlimited Turbos	30 Precursor Orbs After Act 2-25
Tougher vechicles	15 Precursor Orbs After Act 2-14
More Vulcan Fury damage	6 Precursor Orbs After Act 1-17

New duds :
Get 600 Precursor Orbs.