Actually, a better indication of what it's worth is the completed auctions - sometimes what people ASK is out of line.
I was going to say, off the top of my head, about $425+/- and I wasn't too far wrong.
Here are a few more or less comparable completed auctions:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...&category=14912And then there was this nutbar, who sold one for $99 on Buy-It-Now (I'll confess that I looked to see if he had anything else going dirt-cheap...he deals mostly in resistors, diodes etc....who knows!? Got a 100% feedback rating, and if he does this often, no wonder!)
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...&category=14912This one closed at $415, but didn't meet his reserve (so no obligation to sell) His Buy-It-Now price was $699
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...&category=14912He then relisted with a lower Buy-It-Now at $450 and sold it immediately - it was actually a pretty good deal since it included the OS discs, which a lot of auctions don't:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...&category=14912Like this one - similar specs, but no OS, for $465:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...&category=14912Another one similar to yours, but less RAM, for $491:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...&category=14912And last, but not least, two more(?) from the "nutbar" - who this time listed it for $200 starting, and it went for his Buy-It-Now price of $526 for one and $420.01 for the other (strangely, a better equipped one...). He remains confused about the model though - referring to it as a "Quicksilver" enclosure!
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...&category=14912http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...&category=14912So...long story short - you can expect to get between $400 and $500 for it, depending a bit on what you throw in with it (OS disks etc.)
If you decide to list the monitor and G4 together, here's an example:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...&category=14912Given that he got over $600 for both, it might be worth considering. The Sony CPD-G400 has gone for $76-125 for a used one and someone sold a new one for $225. There are some listed now with absurd Buy-It-Now prices of $139-299!
Hope that helps in the decision-making process. I just pass my machines down to the kids...and then the lowest one on the totem pole goes to the basement/donation. So far, haven't had anything worth selling by the time we get to that stage. Right now our youngest has an iMac 266 - he'll get the upgraded beige (G3 500MHz) if and when Mom passes on the upgraded G4 (IGHz Sawtooth with almost a GB of RAM) to son #1. However, should Mom ever be so lucky to score a G5, she will in all likelihood be fighting tooth and nail to keep son #1 off said G5 (passwords - they're wonderful things!)...he has wonderful visions of gaming heaven dancing in his head!!