Aim surplus?
Dsarms?
Psa?
Toolcraft?

If you're looking to save a few bucks, skip the NiB, completely. I'm not saying it's complete waste of money, but if you're on a limited budget, that is an expense I would avoid.

RCA =GTG

I have a toolcraft and it's been flawless

I had a PSA FA NiB bcg and probably put over 500 rounds on it with zero issues. Fwiw I bought it when it was on sale for $99 a couple years ago.

Not on budget in general. Looking for a second bcg. I have a toolcraft now, but want to try a NiB to try something different.

Where did you get it? I only find them at wcarmory.com.
http://www.wcarmory.com/toolcraft-bcg-223-5-56-bolt-carrier-group-ni-bo-t-c-engraved-mpi-c-158-complete.htm

That's where I bought mine.  Even if it's not in stock, sign up for in stock notification.  They get them often.

 

I would grab a PSA premium unmarked while you can

http://palmettostatearmory.com/psa-5-56-premium-hpt-mpi-full-auto-bolt-carrier-group-no-logo-39339.html

I have 3 here now as spares (1 might end up in a rifle before the end of the month )

I have 7 psa that are flawless.    I don't see how they could be any better.

They were $109 Shipped, a few days ago.

I was looking for a NiB BCG for a .300BLK build when a PSA email advertised one at $109.99 which I thought was a good deal.  Out of curiosity I went to AIM Surplus and theirs was on sale for $99.99 so I bought from them instead.  The spec's were the same and $10 is a box and a half of cartridges.  The Nib coating looks great, flawless and looks "thick" if compared to one I bought from Pegasus Defense which is a local company to me.  I havent had a chance to get out and shoot my new rifle but I feel confident in the AIM because of all the great reviews here and elsewhere.  The one from PD is doing fine after 1000 rounds and I expect the AIM to do as well or better.  I wouldnt hesitate to purchase another of either but time will tell which one holds up better.

I thought about trying the AIM NiB but decided on Nitride in stead and bought two AIM BCG's for $93 each. My reasoning: Perhaps a surface treatment would out-perform a coating, but I've been wrong before.

They still are currently. Ordered one this afternoon