Malfunctioning keyboard after spill - Inspiron 600m

Another spill issue; this time it was milk (soy.) I spilled milk on my Inspiron 600m laptop, which I got over 3 years ago so I don't have a warranty or any kind of service plan. I let it dry for a couple of days, removed the sticky keys and cleaned them..  Except for the fact that most of the keyboard doesn't work now, the computer seems to be working normally. Is it possible to replace, or fix, the keyboard? I've heard that if this is possible it can cost over $150. Right now I'm working with a cheap ($20) USB keyboard which is doing the job, and this is fine for now since I'm using my laptop at home for the most part and don't have to carry it anywhere. Do they make special keyboards for this situations? (a desktop keyboard kind of gets in the way.) Any recommendations?

Thanks

John C