There are quite a few now. I followed the 80% world just after it started, but didn’t start then until 2 years ago. I had no desire to machine Mil-spec 80% Lowers as FFL Forged lowers have been so economical for so long. I was looking for 80% Billets. Unfortunately for many years the 80% Billets were almost all 6061 Aluminum alloy and ungodly expensive. Then around 2014 I came across American Made Tactical 80% Billet Lowers. They are 7075-T6 alloy and sold originally for $60ea. The last several I purchased were $68ea., but I think they just increased the price to $74. Still, $74 is not bad for a Billet 7075-T6 80% Lower. I don’t know of any more economical.
But do not think the lower price to mean “CHEAP” quality. Absolutely not. I can show you 4 I have built in 2 years. And I have several more lowers. The quality is outstanding.
As for the LPK, Lower Parts Kit. Over the years? I have noticed a decline in quality. Because of this I choose now to piece together my own kit. I like parts from KNS, all the springs and some parts, I get from from TPS Arms. Other parts are from Gound Zero Precision. I look for all the parts to be machined/turned from billet steel. No cheap cast or MIM parts. I like the springs from TPS as they appear to be Chrome-Silicon. NOT SS.
The trigger is up to you. I really like 2-stage triggers, but I refuse to pay the money. So I prefer standard triggers, machined from good steel. And I perform my own trigger job.