BCM upper with or without Complete Bolt assemby?

[Redstate]

Very new to the AR 15 platform. I am going to build one and have started with the purchase of an RRA stripper lower. I decided to build due to not being able to put out all the money at once and for other reasons. My next purchase is hoped to be a BCM mid-length upper (.556) without the bolt carrier group. I would like to buy the bolt carrier group with it but cannot afford both at this time.
This is the question: Is it better to obtain the whole upper with the bolt carrier group so as to avoid any possible headspace issues or any other potential issues? Basically, what I am asking is whether there is any advantage to purchasing the whole thing at once?
Thanks.

[Kokopelli]

either way will be fine.. If you get them together, they won't be test fired together anyhow.. I would just pick up the BCM upper I wanted and later on get a BCM BCG.. JMO

[Berserkr556]

Basically, what I am asking is whether there is any advantage to purchasing the whole thing at once?
Thanks.

The only advantage is the cost will be a little lower if you purchase the Upper with BCG and CH all at once.

[Kokopelli]

No advantage...

[Redstate]

Thanks for the responses.