The 604WiFi goes for around $250 while the 605WiFi 30GB can be found for as low as $280
but I said before, you can get it for $240 if you have a myspace account by Nov 20th (special discount)

There a few differences to look at between the players
and 605 is thinner and lighter than the 604
the 604 resolution is WQVGA (480x272) and the 605 is WVGA (800x480)
the 604 comes with Opera for free while the 605 you have to play $30 for Opera (and Adobe Flash)
and because the 605 has Flash it can play videos from like YouTube and c|netTV while the 604 can't
the 605 also has "Content Portals" so you can buy or rent movies through WiFi directly