You know, for 3 scalp reductions, you don't look that bad at all. As for Barrera, I'm kinda shocked he's charging that high, placing himself above the HWs, Fellers, Rahals, Shapiros. Pretty arrogant. Unless he's trying FUE, but I've never heard of him attempting this delicate art.
I would think, for decent density, you should stick with the upper suggestions. 2500-3000 sounds right.