Drakuv's heal is an area of effect. The medical bunker you would have to wait for every soldier to be healed one by one. I can assure you that Drakuv is way much better, besides the healing don't forget he also kidnaps enemy infantry, making the 1800$ investment worthy.
One more thing, the Drakuv can also move. Since the Medical Bunker is a building, you would have to pull back your infantry from battle back to the base, or invest it in more Medical bunkers, which I can assure you it will cost you more than 1800$.
The binker would be useful when you are defending. =)