[jordsmi]

While there are some goals I usually have for my engagement, CTR, etc on facebook. The real end goal is your ROI.

I've had campaigns with extremely cheap clicks, but no conversions.

I've always had campaigns with expensive clicks, but it converted so highly that I was making good profit.

So pretty much there is no real cookie cutter answer for this question, especially since you are just paying for likes. From my experience most of IG likes are just bots and don't bring any real traffic.