John & Jeff (CMMG owners) attempt to put out extremely perfect rifles and whether due to shipping or shop incidents, they may have an occasional part the come to the final line with a small scratch, ding, or discoloration and those parts go into a separate bin...
At the end of an undetermined period, they start assembling rifles, using those parts, and price them accordingly... I know both of them and how particular they are about their reputation, and what they see as an imperfection, you may not notice...
IMHO, there is no significant difference between the "Bargain Bin" rifles and what they put out in their regular line, other than appearance or mis-matched parts...They all shoot and after bouncing around in a truck or car trunk, in two months you won't be able to tell the difference...Just my $0.02 worth...
You just don't have the option of specifying various upgrades you may desire...