jking,
I've worked for the Fed. government for the last 14 years and the answer to your question is, they're notoriously SLOW. Also, it's not much harder to buy something that's not on the GSA list, you just have to fill out a special purchase order instead of a regular purchase order. The requirements are that if you want to purchase something and someone on the GSA list has it, then you MUST purchase it off the list. If no one on the list has what you need then you're basically free to purchase it from whomever you want.
If you find yourself in a fair fight, your tactics suck.