Late 2008 MBP 15-inch corrosion on logic board (photo) -- won't turn on

My MPB late 2008 15-inch won't turn on. I get a black screen, the sleep light is solid, the hard drive hums, but then after 3 seconds it turns off. POST portion of bootup won't run. After reading some on these boards I figure its the logic board.

Took it into the apple store, they say water or user-caused damage. $1200 bucks to fix (i'm out of warranty, but i guess it wouldn't be covered on warranty any how). Might as well buy a new comp at that price. I have never spilled water or other liquids on this or used it in otherwise wet environments, but it is what it is.

Went home, opened up the comp to see the logic board's damage, and it does look like there is some corrision (see below in photo, copper/salt covered bit).

So I'm looking to repair on my own with third-party. I'm wondering if anyone else has seen this sort of "corrsion" before and succeeded in switchign out the logic board and getting the computer working again?

If its salvageable, i've got a quote from a local guy who can do it for $330 with one year warranty on the whole computer. Is that a decent price?

Thanks for any help.