Is there somewhere in the rules i missed where Players can permanently expend Profit Factor?

For instance, say they want something, they want it now and they're willing to expend permanent Profit Factor to get it, rather than risk missing Aquisition rolls. Let's say they are aware of a very rare item and starting out don't have a very good chance of aquiring it normally and they want to make sure they get it before a rival RT does...

Is there provisions for that in the rules? I'm going to read it again, but the only way I see to lose PF is via Misfortunes...

Haven't read anything about it either, but I'm thinking of allowing what you said (perhaps allowing retroactively spending Profit Factor to lower the test difficulty for aquisitions on a 1:10 or 1:20 basis) as well as requiring profit factor to be spent when upgrading or buying ships - "Sure I can hand that teleportarium over to you... say, would you part with the secrets of the Inaran Route with it?".

In the book it's misfortunes only. Personally I plan on having the PCs spend PF on ship items, ships, and extremely rare items. The PCs could other wise go on an endevour to find an item or convince a faction they are worthy. On the flip side they can get PF by handling over ship items, ships, and extremely rare items. (General at 1/4-1/2 of the cost of buying said item with PF.) Thus salvaging an entire ship can be very profitable as it should....

Actually, they can lose (and gain) profit another way. Commerce skill (pg 273). For every acquisition Test attempted, they can make an opposed Commerce Test (or the NPC can force a Commerce Test!) It's an opposed test, and each degree of success (for PCs) increases PF by 2, and each degree of failure (success for NPC) lowers their PF by 2. One opposed test per Acquisition Test.

Yes, but that's only for that test if you read the last line of the pargraph. "Both increases and decreases to Profit factor apply to a single Acquisition Test made immediately with that trader."