I found some RAM for $195.00 here
The video card for $169.00 here
Power supply $50-$100
Any DVD burner $35-50$
$450 upgrade.... seems pricey. You can get 2gig of PC3200 RAM for the cost of that RD-RAM. the PC3200 wont fit your Mobo
If i were you and i really wanted to upgrade this machine, i would forget the ram and power supply. Just go for the video card and the DVD burner.
If you don't have enough power to run your upgrades, then you can worry about a power supply.
thats still $200 for a one-year upgrade. thats pretty expensive.
1. Just wait.
2. Build a monster of a machine when you do build.
3. Don't waste money on that old Dell.
BTW: Why do you need to upgrade? Newer games?