MBP Boots sometimes - If logic or main board bad, what can I expect?

Question

The Symptoms:
MBP Boots only occassionally. When it does not fully boot you can hear the disk and fan very slowly wind up, over the course of a minute. There is no startup chime. The screen never comes on and remains dark, no external monitor comes up, the keyboard and usb ports are disabled, and the latch light glows steady and dim. It doesn't repond to startup key commands and the disk you can hear doing something but nothing comes on.
I've swapped out the ram, booted into safe mode (when I can get it to boot), run disk utility and disk warrior, among other tools, booted from a flash drive to run diagnostics. Disk checks out fine, zapping pram, resetting smc, all this does nothing. Genius bar did diagnostics and couldn't find anything wrong, but offered me the repair depot.
Conclusions:
So after researching many threads the past few days, a trip to the apple store with some diagnostics, and further testing/swapping ram/resetting pram and smc, I've come to the conclusion that I must have a problem with the logic board or main board. My computer only starts up after about 5 cold boot attempts and/or some of the above processes. Once it's up and running it's fine. When it doesn't boot the drive spins up, the fans come on, but the screen/keyboard/usb etc are all inactive, and the latch light is a steady dim white. When the computer does boot it runs fine.
Question:
My question is, should I expect more serious problems in the near future, or is it at least possible that I could limp along for some months in this condition? I have the option to possibly submit it to repair depot for refurbishing, but if I could make it at least through some june update news I could make a more informed decision about what to do.
Any and all information, experience, or suggestions are much appreciated. 

Answer 1

I agree with you that the people who staff the genius bar are not genius' but technicians, and are of varying degrees of competency.  However if you are offered what is referred by some as a 'depot repair', consider it very seriously.
My experience is as follow with my old 2006 MBPs:  Several years ago I had a serious problem with the display and was offered said repair that would fix the display issue and any thing else that was found to be faulty.
The following was replaced;
     The Display
     The Optical drive
     The Airport card
     The top cover
          (the old one had dents in it and there was no expectation on my part that it would be  replaced)
      The keyboard
      The bottom case
      The RAM cover
The total cost was a fixed price of $310 which was told to me up front.  That is what I paid (plus tax).  The invoice showed a total of $1240.  I still have that MBP and it still looks and operates as new.  This repair was not done locally, but at an off site location.  I suspect it was done by very well qualified technicians.
If you are offered such an option and your budget can accommodate it, I suggest you take it. You also get a 90 day warranty with it.
Ciao.