Keyboard not working, left click behaves like right click

Hey, i have a problem. My macbook air was completely alright when i was using it in the evening. I shut it down, went to bed and then i woke up in the morning, turned on my laptop and all of the sudden, the keyboard didnt work. Also, when i left clicked the trackpad, it behaved like when i do right click(the window with i.e. "copy, save as.." popped up). But EVERYTHING else was/is working like a charm. It feels like the laptop is completely okay, just the keyboard and trackpad are not working. This happend like a month ago. I took it to my local Apple Service Provider, and they diagnosed it as water damage(altough there is no possibility i spilled water on it/somebody spilled water on it). They sent me some pictures. The only part showing some damage is a little place, right where the mag safe connector connects to the laptop. Its maybe an inch by inch big. Aparently, they want me to pay 1000€(1300dollars) so they can fix it. They want to change the whole motherboard, in order to fix this one little piece of it. I would not say a word if the computer was dead or had some other main damage, but i think its ridiculous to pay 1000€(i can buy brand new macbook air for this price) just to pay for the keyboard/trackpad repair. Also, i tried to connect my magic mouse to it and it does the same thing. When i do left click, it actually does right click.
PLEASE help me, or tell me if its really neccessary to remove and change the WHOLE motherboard or if its reasonable to pay that price for this repair.(I live in Czech Republic, where those repair guys would tell me anything to get money. So i dont really believe them, its a water damage because i didnt spill any water on it) And if you have any suggestions what else could be the problem, i would be glad if you shared them with me.
These are the pictures of the broken/damaged piece:
http://i39.tinypic.com/ms0z2s.jpg
http://i44.tinypic.com/2zxnnnd.jpg

THANK YOU FOR YOUR HELP

 

So the keyboard and trackpad parts are located right where the corrosion is? Cant i just get this exact part repaired? I forgot to mention - trackpad works well right after i turn the laptop on. It takes like a minute or two for it to start working the way i explained. And also i still dont know how is it possible there is the corrosion when i didnt spill any water on it and I dont think any of my family members would not tell me if they did something to my laptop.

 

Ohhh thats not what i was hoping for, but anyways, thank you for your response! I really appriciate it. Do you recommend buying a brand new macbook or have it repaired? And why is it that the trackpad works right after i turn the laptop on and stops working after couple minutes? I cant believe my laptop is working and everything but i cannot actually use it. Makes me go insane

 

Its 11inch MBA, 64GB SSD, late 2010 model. To be honest, i want to avoid selling it and getting a new one, altough after i read your post, i guess thats the only thing i can do. It just seem so ridiculous for me to sell my working almost new laptop(or to pay 1000EUR) just because the keyboard and trackpad are not working properly.
Another question, can i buy an external keyboard? Is it going to work? Im asking this because when i connected magic mouse to MBA, it started doing the same thing as the trackpad was doing. So im guessing the keyboard would not work either?

 

Thanks for helping me. Its under warranty until January 31. And thats the thing, they told me that because its "water damage" its not covered in apple warranty and i have to pay for the whole repair. I still dont know how possibly could it be water damaged when there was never ever any water spilled on it or anywhere near it, but okay, whatever they say. There is no official Apple Store here where I live, only authorized premium resellers and service providers.
Oh well, i might just do what you suggested. Theres gonna be a LOT of parts they can re-use, so lets hope im not gonna lose much money when i buy a new one.
Also, do you think i should wait for the 2012 model or just buy the 2011 one? I was pretty satisfied with my 2010 model(my first macbook, never switching back to windows) the only think i was missing was backlit.