To be honest, I don't quite understand why you'd be happy to buy anything other than an Epi & swap out parts, but not buy an Epi & swap out parts...I hate epi's (except MIJ ones) cause they sound dull.
...everything else could be swapped in time.
When it comes to Gibsons, they have no 'magic' way of producing guitars cheaply in the USA - you'll always be paying for the higher cost of labour compared to Korea, China, Mexico, Indonesia, etc. For equal prices, you're likely to get better quality parts/finishes on a non-USA model, but nothing is guaranteed, especially on budget models where quality may vary more - whether it's parts, finish, QC. etc. Note that this does NOT apply to Japanese production; Japanese manufacturers are also forced to produce outside Japan due to labour costs, MiJ models like the Yamaha SG are expensive. Fender MiJ are more expensive than Fender MiM.
As for Gibson's quality control, several dealers I've spoken to, or I've heard comment on the subject, said it has improved in recent years, particularly in 2015.