2K metal to take out the majority of the time one other unit if you are lucky(micro manage and he gets aggressive bringing unit forward). There is no metal left behind. I think his cost is exactly where his usefulness is.
I would even argue he is absolutely required to counter other units that get produced. Ex. Funnelweb, Paladin/Detri and/or cyclops. The designers have as of right now done a pretty good job in balancing all the units across the board. This is easily proven in that everyone gets access to every unit(No Factions).
The natural gameplay shows which unit is better if a strategy is meta.
This is always a lowblow in a discussion to turn the attention to something else but i am going to do it.
If we are going to talking about cost effective or how the unit is unfun as the topic has turned into. Let's please talk about iris. OMG Really 0.6K for a unit that cloaks all other units in a HUGE area of effect. It moves super fast and the unit itself is really small. Like wtf. Also when it's cloaking field is within your units. Your units don't even notice. Like don't even give a Predator blur (like from the movie predator).
Then to decloak units you have to be close enough to the unit. What the heck is that? Please add a counter to cloaking. A unit that reveals cloak in some way. I honestly think all planes from the plane factory should have an area of effect that decloaks units. If nothing else then give this ability to the owl.
Yeah Detri and Dante are terrible units. Don't build em.
Love to hear the feedback. Tear up my comments. But be logical about it.
Most importantly keep playing zero-k.