Gohan - 14,000,000,000
Vegeta - 6,500,000,000
SSj2 - 13,000,000,000
Due general apathy recently, I stick with the official multipliers for the Super Saiyan transformations, meaning this battle would be dead even. It would force Vegeta to really focus and use his supposed "battle genius" attribute to overcome Gohan, who at this point isn't a complete slouch, being freshly trained by the greatest martial artist in the series.
Vegeta 2/10 times for me.