An AAC brand is about $980 on sale. It has a KAC rail which is a $300 part. It has NiB carrier which is nice. The barrel sells for about $400 on its own. You could not build one for much under $900. And it has been though lots of testing.
A good value upper is about $500 from...
It is true that the 6.5 is more powerful than 300 BLK in most or all barrel lengths, but larger bore cartridges do make better use of shorter barrels. So while the larger bore and smaller case won't make it surpass the 6.5 G in power, it will come closer to its max potential in a 16 inch barrel...
There are now Handi Rifles shipping in 300 BLK.
http://www.300aacblackout.com/resources/300-BLK.pdf
http://www.300blktalk.com/forum/
https://www.facebook.com/300aacblackout
I put all the latest updates here: https://www.facebook.com/300aacblackout but this gel shot shows how well it works at 300 yards, even from a 9 inch barrel.
Midway had the good ammo in stock yesterday, but it sold out already: Shortages should be taken care of by Feb.
UMC Ammo 300 AAC Blackout (7.62x35mm) 115 Grain Full Metal Jacket Box of 20
Actually they brought a 300 AAC BLACKOUT PWS upper:
MK109 Upper, 300 Blk - PWS Uppers - PWS
They were shooting Hornady 300 Whisper(R) ammo in it. Hornady ammo was specifically designed to be compatible with the 300 AAC BLACKOUT.
One should not shoot 300 AAC BLACKOUT in a 300 Whisper...
The 155 is not designed to expand - that was a military round. There are two expanding loads from Remington coming out. One is an Ultra-Bonded Core-Lokt, and the other is a 125 grain AccuTip-V. Here is a video of some expanding loads:
http://www.youtube.com/watch?v=hRw-ypBgrKo