$400 is only a set of pickups short of a Mexican Fender. $800 is more than some PRS SE models. I just don't see it working out, unless you can reduce the cost by just not including hardware besides the pickguard. And even at that point, there are plenty of companies that already offer similar priced kits (or just individual bodies and necks) that are fully customizable outside of shape.
I think PBG has found the sweet spot in cheaper kits that are priced to allow for flexability for every builder's budget, from simple oil finishes and stock hardware, to full on nitro finishes and top of the line hardware.