I think the state of Super Saiyan level 1 is pretty much relative to your own personal "base PL."
A good example: I have 2000 PL. When I get to say, well, 6x that, I can go Super Saiyan, which probably doesn't increase your power as much, as it more likely increases the potency of what power you have (i.e. making your ki stronger, allowing you to use more ki to enhance your strength or some such ****...I'm tried and havign a ahrd time wording it, I hope you guys get what I mean though).
So, with this theory being taken for granted as being true, we can then understand this better:
Vegeta's base PL (which by the Buu saga must be high) and Goku's base PL (which by the Buu saga must be DAMN high) get added together/multiplied up (whatever the Potarra earrings do) to get Vegetto's base PL (aka HOLY **** high).
From there, we must understand that Vegeta and Goku have both obviously exceeded more then the necessary SSJ multiples of their respective original "first base" levels (the levels above when they formed Vegetto would obviously be their current base, as opposed to their original strengths).
This means that when they merged into Vegetto...they were supremely powerful, AND past the SSJ mutiples of their own power levels, meaning Vegetto's uber power was just as far past his necessary multiplier for SSJ.
Meaning Vegetto's SSJ state is INSANELY POWERFUL, maybe upwards of 12 times Vegeta and Goku's individual SSJ power with even small numbers involved.
Well this is all theory but it's the only way I can really figure it out. What do you think?