Dell Inspiron 6000 HDD read error

Hello,
i have a dell inspiron 6000 that ive gotten up and running twice, but now there is an HDD read
error. I have followed all the threads about this topic, so please dont lead me thru the process
of figuring out whats wrong, as I already know whats wrong. Whats wrong is the hard drive is dying. What I dont know is how much does it cost to replace the hard drive, where do i get one, etc.
Thanks,
Spencer Hopkins