Don't see any price here but it looks like mine, without the add on.

Velocity isn't known for deceptive sales. They're 3 miles from me. Treated me exceptionally well when visited. That who's selling it?

independent seller...

Ok then (2nd Post)  Buy it elsewhere to be sure then. Tons to choose from. Best of luck.

I can't really see the inner label on the helmet real well, but ask the seller to provide a photo of it. Things like that I also want to see a receipt. If it's the original owner they probably have an email somewhere from where they bought it and you can use that to verify with.

It looks legit. I'd want to see the label. Price depends on the model. Based on the ARC rails it is definitely not a FAST SF or MT. Shape of the shell and Velcro lead me to think it is a FAST XP or FAST LE with the shroud swapped out. Arms Unlimited is blowing out the SLAAP plates for $100 and was selling a FAST cut helmet for around $700 a while back. Based on that combo that is likely where your seller sourced those items. Looks like it could be a FAST SX and I seem to recall these were like $700 when in stock.

Yes

Can't tell what model that is, but that's an MBS shroud (their most expensive one).

At a distance, everything looks right. Is he including the SLAAP too?

Well it looks legit, but I'd like to see a close up of the label for sure.  If it is supposed to be a XP, I have the same helmet, and I'd swear mine is a little thicker.  Also ask him what the (main) shell weighs if he knows.  It almost looks to be in between a XP and (super high-cut) SF, as far as thickness goes.  

What I also wonder about is his mil-sim AR replica there, which is neither here nor there, but need to know if this guy uses "Real Steel" kit or repro.  That might be an indicator of whether it's legit or not.  I remember when I super high cut my XP, I removed the inner label (which comes off pretty easily) in the course of sealing and re-finishing the shell.  The thought crossed my mind that it would be easy to put that label on another helmet; just sayin'.  If the price seems too good to be true, well, then maybe it is.

I don't know any of the parties involved here; just diagnosing from the internet.   God bless and good luck to all.

I'd say it looks legit as well, especially with the accessories, but like I said earlier I'd want some sort of receipt from the original purchase. If it's some sort of life/limb product, I'd like to know the paper trail.