I think you are pretty dramatically over-estimating the cost of seeds! If you buy in any kind of volume, even top self are cheaper than that. Can't be buying one at a time though. You also end up with loads of freebies, I mean it really ends up cheaper than you're thinking.
In hydro it is possible that clones save a little time, but I am skeptical. In Coco, my clones absolutely take longer than my seeds. I have started twice with really good clones from a dispensary. So I am not even thinking about the time it takes to get them rooted. I start with rooted 8" healthy clones - and starting with a seed is faster. They cannot keep up or compete with seedlings... it's not even close.