Look my girls at 19 days into flower with this feed schedule. - total nutrient cost $2.21 per OZ harvested dry bud. So no it's not expensive!!
This is my tweaked regimen, & my girls love it. I got 156 oz under 5 kw 5 ea x 1k W reflectors.
Typical 8 week flower cycle after 6 week Veg cycle...