Currently Being ModeratedNov 6, 2013 7:20 AM (in response to Selvaraj)
Look for replacement parts on iFixit.com and Powerbookmedic.com. Instructions on replacement will also be available.
Currently Being ModeratedNov 6, 2013 7:22 AM (in response to Selvaraj)
The keyboard is integral to the top case, so they are quoting you a price for a whole new top case. You cannot buy the keyboard separately - it comes as part of the top case There is also extensive disassemble/reassembly involved in replacing the top case.
see http://www.ifixit.com - the cost of a new top case for a say, 2011 unibody MBP 15" is about $300, then add on the labor to install it, and $400 seems very reasonable to me.