Unless it's a laptop hard drive, or a SCSI drive you paid too much.
You didn't mention any interface, speeds, or other specs, but the going rate for an internal 160GB drive is around $50-$60, without any rebates.
How much do you know about replacing HD's? Are you familiar with the different types of interfaces, speeds, cache, etc? If so, shop online for one. I've used NewEgg multiple times and have been very satisfied.