I have a Pioneer A04 and the recommended media, as I've heard, is Verbatim.
Well, where's the cheapest place that can I buy Verbatim DVD-Rs in bulk?

Also, if I can't find these at a good price (for me), what are other brands that will work in backing up PS2/XBox games?

I have had no problems with DVDPro media, which I buy at CdrDvdrMedia.com. I buy mine for 1.42 a piece, 25 pack, with free shipping. Some people have not liked dvdpro, i dont know, i have no problems with it. CdrDvdrMedia have a current promotion type thing where for 20 dollars you get like 2 each of 5 different kinds of dvd-r's to test out what your xbox or burner likes the most. So you can always buy that and test your xbox dvdrom. Verbatim are way overpriced, and I would not recommend you wasting your money on that media. Anyways, good luck.

I get DVD-RWs for $2.25 each from a local shop in NY (I'm sure they would go lower for bulk purchases).
I have tested these on 3 different X-Boxs (2 were 3944 and 1 was 4034), and they have worked evey time with no problems.
They dont have a web site and I dont know there number off hand, but I could find out for you and anyone else that is interested.
Let me know if you are interested (PM me),
ZS

all i know is not to buy from yesbuy.net
they're utterly horrible and slow
and probably will give you crap as a dvdrw

Actually I ordered from yesbuy.net and was very happy with what I got. The DVD-RW's are PRINCO brand (If you buy 100 they come out to $1.05 apiece) and they work great on my XBOX.
Satan00 did you order DVD-RW's from them, if so did they not work at all for you or where they just slow at loading?

try meritline dvd-r on meritline.com, they work fine for ps2 games and they are cheap too. They also have bundles of dvd-r's.

New Info:
I can get DVD-Rs for $1.25 each and DVD-RWs for $1.75 each.
If anyone wants some let me know (PM or Post).