A separate pinpointer is not an absolute necessity. Worked many years without one at all. If you practice pinpointing with your rig and get very good at it, you will be happy and wonder what you're missing.
I've had many times where I got a signal and knew exactly what coin, how deep, and where it was depending on which one of my machines I was using. I could very often cut a small plug down 6" and pop it over and there's the coin, either sitting on the end of the plug or in the bottom of the hole.
Then there's them other times. Like I said, one of the modern pinpointer options is not an absolute necessity. But it is in my view, without a doubt, the best metal detecting accessory ever made. Better than headphones, better than the best digging gear. Maybe not better than batteries, but batts are not optional until after 2016 and the advent of the low power circuitry that will be powered by bio-inductive coupling.
Of course that's going to come after the 2015 multi-point PI scanning cellular coil breakthrough. That can sample literally hundreds of signals a second from a multi-dimensional array to build an exact image of the target with depth and orientation accuracy within +/- 4%.
So for a couple years you have to hope you have the biggest, most powerful tool array at your disposal, one that can blow coins clean out of the ground. I know what you're thinking, did I dig all the targets or didn't I?
Well did ya, .....