The $450-range Toshibas are pieces of shit. The 15" laptops have horrible ergonomics and build quality. They feel like they're going to fall apart if you move them around too much and the keyboards are off-center from the screen which makes them horribly uncomfortable to type on. The number pad they so "thoughtfully" include isn't used nearly enough to make up for the ridiculous ergonomics. Even the smaller laptops are bulky and don't fit well in backpacks or messenger bags. The power supplies are monsters and have very fragile feeling DC connectors. If you tilt your laptop back a little too far you're likely to snap the damn thing off in the plug. They're also really unbalanced so tilting your screen back too far will cause your laptop to topple backwards.
You can (and obviously will) naysay Mac laptops but at least some thought went into their industrial design. They fit neatly into bags because they don't have oddly shaped bottom panels that catch on things. The MagSafe adapter has saved me from destroying my computer on a number of occasions, and they go to sleep and then wake up from sleep very quickly. I'll spend the extra money to get a laptop with features that actually make it nice to use. Bullet point features like a faster CPU or RAM don't mean a whole lot when I'm putting it into or pulling it out of a bag a hundred times a week.
The justification would be the same as for the nicer car, if the car feels nice and has better fit and finish it's probably worth the extra money. You interact with the fit and finish every single second you're using the thing. If it's build cheaply you feel it every time you touch it. I'll get a car with power windows and locks so I don't have to check every door handle when I get out like a rube to make sure they're all locked. I can roll all the windows down at once when it's been sitting in the sun so I don't need to crank the AC when I get in it. I'll get the more comfortable seat that's easier to adjust because I sit in it every single day.