Sorry to hear about your unfortunate situation. It is always heartbreaking to hear these horror stories about how a fantastic laptop can become an expensive doorstop. An MJ-12, too.. good Lord, that's gotta hurt.
Personally, I'd balk at the $1200 T&M quote from that Computer Repair company. That's kind of steep to simply have a motherboard replaced - even if labor was 4 hours, billed between $60 and $90/hour. This company probably knows the laptop is worth $3500+, and are charging based on that fact alone.
The lack of a Non-Warranty repair option is the sole thing that made me nervous about purchasing my first Alienware. It still makes me nervous to continue owning a 7700. Remember how Alienware totally SCREWED the previous model owners with the promised Video Card upgradability?
I really don't like the fact that Alienware only offers replacement parts if it's a warranty repair. There's no T&M option to "restore" a damaged notebook, even though such an option could be profitable. (The markup on "Factory Replacement Parts" is how a lot of Auto Dealers stay in business.)
Honestly, it's the silly business-policy stuff like this that makes me want to create my own Notebook assembly company, using some of my old contacts in Taiwan.
GeckoWare Laptops... hmm.. nice ring to that. Wonder how a pair of glowing gecko eyes would look...
Forgot to add... the fact that your laptop partially powers up (the onboard fans are working?) suggests your motherboard may yet be salvagable. I'd suggest a full disassembly/reassembly of the entire unit to check for loosened connectors. You know, it could be as simple as taking out the battery, letting the machine sit for a few minutes, then plugging it in. It's daffy, but it has worked for others.