I got a new PowerMac Dual Core 2.3 with 3gb memory and 1 500gb hard drive earlier this month. I'm ready to start loading it with HDV footage but I'm going crazy trying to find 500gb internal hard drives for the second drive--are they all really 650 dollars? Does anyone know anywhere I can get them slightly cheaper? Should I have just ordered the second hard drive from Apple when I bought the computer? It almost looks like it would have been cheaper. I'm doing a large project so I'll need a vast amount of hd space.

Thanks in advance for your help

Go to Mac solutions on Wilshire. get a G-Raid 500GB for $499. See http://macsolutions.com/ipodspecial2.html

I already have one =)

Computer retailers like newegg.com sell 500GB SATA drives for much less than 650.
http://www.newegg.com/Product/Product.asp?Item=N82E16822148108

Normal SATA drives should work in Macs fine from what I remember. You have to go into disk utility and format the drive (non-journalled, OS X).

If you don't need the portability of externals, internals are usually cheaper, more reliable (no firewire sharing conflicts), and faster. Promax has a product that lets you cram a whole bunch of SATA drives inside a G5. You could figure out how to do the same thing yourself for a cheaper price, because they just resell the solution as a convenient time-saving kit + support.