Dragonball Black said:
Private Ryan said:
@Dragonball Black
Chapter: 510 (DBZ 316), P13.1-6
Vegeta: “Don’t hesitate for my sake, and finish him off! With that Super Saiyan 3, you should be able to completely wipe out Boo with your ki once you gather it with all your might…!”
The above quote is in reference to Pure/Kid Boo. And Boos can regenerate all damage done to them, so the fact that Goku didn't damage Pure Boo much is a moot point. Even taking that into consideration, the two were pretty much evenly matched, with Goku having a slight power advantage.
So I'm not gonna take any type of power scaling vegeta is doing/ saying as gospel seeing as he thought putting out ALL his power at a SS2 Majin in one fiery explosion would be enough to kill Fat Buu, the weak one.
Goku also states that he can wipe out Pure Boo. Here is the full quote:
Chapter: 510 (DBZ 316), P13.1-6
Vegeta: “Don’t hesitate for my sake, and finish him off! With that Super Saiyan 3, you should be able to completely wipe out Boo with your ki once you gather it with all your might…!”
Goku: “Ye…yeah…I’ve been thinking of doing that as well since awhile back, but…I haven’t gotten the chance.”
Vegeta: “Eh?”
Goku: “
If I want to wipe him out, I gotta gather ki for about one minute.”
Vegeta: “One minute?!”
Goku: “Dammnit~~~
If it was with the Potara, I could have done it in one blast. …..Cheh~~~I guess I went and showed off too much. But I thought things would go a little better than this…!”
Vegeta: “…S …So you weren’t thinking of me…”
Not only does this show that SSj3 Goku is capable of wiping out Pure Boo with a charged attack, but it also shows that SSj Vegetto could've obliterated him easily. Vegetto, in turn, is an ant to Blue Goku. What chance does Pure Boo have?
Buu took damage against Mystic Gohan and when he Fought Super Saiyan Vegito. Significant damage that he didn't take when he fought SS3 Goku as Kid Buu.
The examples you listed are not comparable. Ultimate Gohan and SSj Vegetto were both far stronger than the Boos they were fighting, while SSj3 Goku and Pure Boo are both rivals in power. Pure Boo is also far more animal like than the other Boos, and thus he is able to ignore pain and damage far better than the other Boos can.