Hello 7angofragger, and welcome to The PC Guide Forums!
Don't trade. Your PC is much better then what he wants to trade you.
What motherboard is in the workstation/server?
The Xeon 2.80GHz Nocona is the slowest in that series (2.8GHz-3.6GHz) with a 800MHz FSB and 1MB L2 cache.
If it had a single 3.8 Irwindale it would be almost as fast as your AMD 4000+.
Will the motherboard support Irwindale Xeon CPUs 800MHz FSB and 2MB L2 cache
A single Xeon 2.80GHz Nocona 800MHz FSB and 1MB L2 cache = a P4 2.80GHz Presscott core 800MHz FSB and 1MB L2 cache.
Your CPU is much faster and you wouldn't see a significant performance advantage until you add a second CPU.
Nocona core Xeon CPUs are getting hard to find and Intel made 2 different 2.8GHz Nocona CPUs DO stepping and EO stepping and when adding a second CPU the stepping of the CPUs must match.
Most games will not use the second CPU so you would more or less be extreme gaming with a 2.8GHz P4, that doesn't sound very extreme to me LOL.
If it had a couple of 3.8 GHz Irwindale CPUs it might be worth the trade.