Macbook spacebar barely working

About a week ago, the spacebar on my 13.3" Macbook started giving me problems - I have to hit it squarely in the middle and with a lot of force to get it to register. I tried removing it and cleaning it, to no avail. And I've been told by repair shops that this will run me upwards of $200. Is there a cheaper and easier fix?

I used to have problem with left arrow key in my macbook a1181. It worked but I had to press it harder. I took the top case off and sprayed it with isopropyl alcohol. Let it to dry for few hours and voila. Works fine now.