MArcomage

Far sight and +15 tower for 5 bricks? Maybe raise cost to 7-8?

Well it has a "negative effect"

It's negative as is, but look at other concepts, like Goblin King, Cave goblin or Goblin elite. To have 3+ Goblins is a benefit for this concept pack.
And I'd take something like Dark flame or Purifying fire in goblins deck...

I've rised the cost, it should be fine now