Exactly. If all the author wanted was an affordable notebook to replace his >5 year old PowerBook, then he could've bought a $1,200 MacBook Pro [0], which has FireWire800 and Thunderbolt ports. The low-end MacBook Pro is far more capable than his old PowerBook, and it wouldn't cost him anywhere near $3,000.
Regardless of which OS you'll choose to run on it, I doubt a Dell Mini 9 netbook will be a reliable mobile workstation. The author indicated that his income is dependent on him having a functional notebook. One would think he would reserve at least $300 a year for hardware.
I'm left wondering whether the Dell Mini 9 will serve him for the next 2.5 years. If not, then a MacBook Pro would've been cheaper.
The more reasonable framing would be $600 Dell netbook (what he ended up buying) vs a low-end Mac laptop option.