In my opinion, LPK is just a bunch of springs, pins and fire control group. Why should we pay more for those springs and pins?
Should use the money to invest a better FCG or other parts. I use PSA LPK without FCG, then use Spike's buffer spring & buffer, KNS anti rotating pins and ALG combat trigger. Then Magpul MIAD, ASAP, Bad lever, trigger guard. That's the way i build.