Well, I priced it out...
I can get KYB's (the OEM equal) for approx $260 shipped.
The Koni FSD will be approx $580 shipped.... a little over double the price...
The thing about the KYB is that they keep saying it will be restoring your car's original ride. Well, the Mazda 3's ride was never that great to begin with from a comfort perspective, so that is not a really good advertisement to begin with
As for what it will be used for....it would be used for a daily commuter and going out of town on weekends, but I got a new job that is walkable, so it looks like it will be used just for getting out of town on the weekends.