Questions on hp ze4900 laptop

Everyone has been great on here helping me out. I feel this is the best place to ask. I'm not quite sure I trust what tiger direct support told me.

I have a hp pavillian ze4900 laptop that needs a new hard drive. My husband said he is sure it is the hard drive that only needs replaced. I have had it for about a year sitting around and being moved around collecting dust. Now my daughter is interested in having a computer of her own. I wanted to try to give her that one.

My first question would it be worth getting the hard drive. I'm a little apprehensive that it only needs a hard drive, but that is just me. She will be mostly playing games on the computer for now. She does like going on the net to find information every once in awhile.

Second question: If I do get a hard drive, I would want to get a bigger hard drive than it would have came with. Depending on the price between 60 to 100 gig. I called Tiger Direct and the rep told me segate st32110a 80 gig, and they had it for $77.00. Well, I tried to find it on their site, and couldn't.

Can someone point me to the right direction to a compatible hard drive at a reasonable price. I don't want to mess this up.

Thank you very much.