I would say to wait on buying a dvd-rw. Those suckers are running for about US$450 and the blank discs are running for about US$1.00. In my opinion, thats high. The regular CDRW and the blank cdr’s cost about that much at one point, and the price of those have come waaaay down.
So I’m guessing the price on dvd-rw’s and the blank discs will come down as well. They are currently much cheaper than what I paid for my CDRW when I got it 2 years ago. New technologies always start out pricey and come down as time goes on and more people start showing a desire to buy these products. So my advice to you is to wait it out! I know its hard, but you will have paid alot less that you would pay for one now. Good luck!