How significant is the extended breath holding? Perception 8 is a high price to pay.

I think it is about half AP cost to hold your breath as far as I can tell.

thank you very much.

I may just invest those points into agility to compensate. I'm really only a fan of the perks up to 4-5 in Perception so I hated to pump more points into it.

On the one hand, I feel like the sniper perks are super expensive (both in special points and low utility perk 1). But thinking on it more, this is just the cost at using VATS and AP at extended range.

Though I've never been out of breath, it does consume AP.
I don't use the AP anyway since VATS seems far worse at long distance headshots than manual.
Perk up the Sniper and it solves the vats accuracy problem while giving you enough AP savings to leverage it.

Sniper is really good, the random stun knocks deathclaw down, the only bad thing is it makes people with power armor fall through the earth.

Yeah, I can see that. I don't use VATS really unless I am close range using a pistol. I'd rather get the AP points from Agility and call it a day since I use the sprinting perk and want to delve into blitz.

The second star is excellent, knock down happens a lot, and it helps with beasts like the Deathclaws a lot