Lol, more kids trying to hack games eh?
.SFO = blah, unimportant
.PFD = ?????
.bin = Most important
A .bin file can be considered the game's data and functions that you would want to edit.
I bet your thinking, "OH SHIT, I can edit a game and be a cheater!!!!!"
LOLWUT? no quite
Game data has a series of protection, could be encrypted, who knows?
For one thing, you would have to reverse the data if it was encrypted. Once decrypted, you would then have to find those nasty checksums. *I have seem checksums to check checksums, careful* You would have to taper the checksum (not disable it) to allow what you want to increase/decrease.
Example time:
You have 30 pieces of gold. You find the hex string, change the char to say 50, but the data comes up as corrupted as you try to boot up the save in the PS3.
Ok now what? Find the checksum. Search in the hex, and once found, you would typically increase it.
maybe something like this: check data '30'; If '30<X'; then 'Save Data corrupted'
(NOTE: THIS IS FASLO: FAKE. NOT REAL. Just a minor example for you to understand + Fake C++ skills I know

)
Edit the line to maybe:
check data '50'; If '30>X'; then 'Save Data call' return();
I have really looked up any legit ways to do this, nor took my time to check any guides. This is all from my speculation and probably this is the way it works.
Enjoy.