First, I wouldn't spend that even if I won Powerball.
I have heard self-defense guys say that serrated knives get caught in clothing and do not cut smoothly and they won't use them. If applied to broadheads, then I can see how a plain blade is better. I have a few serrated knives, and I think they just look meaner is all and are a lot harder to resharpen. If you follow Spyderco's recommendations on sharpening, then you slowly round the teeth over. The only advantage I've found to a serrated knife is that you can cut tough stuff like cardboard and carpet longer without needing to resharpen as often. Also, they tend to rip through those materials, but it is not a dynamic slashing movement. And also, you don't get anything for free because you have to pull a lot harder to get that action with them. So, if the same is true for broadheads, then it might limit penetration.
For these reasons, I've never used a serrated head or considered it.