And you didn't get one at home depot, why???

It's a simple case of marketing. You can go to a place like Micro Fasteners and buy 100 servo screws for about 6 bucks or buy a package of 8 at the LHS for about 2 bucks.

Just like you can buy a can of beans at the grocery store for under a dollar but the local convenience store sells the same can for $1.98