If you want to build, build .
If you want to shoot, buy.
If you want true "sub moa", reload.
I never got a bargain buying a cheap gun, and I have yet to regret buying a gun built by a top 'smith-- and they don't cost much more, either.
Here is what I did- bought a complete RRA nat'l match lower and a stripped lower. A RRA varmint upper.
Now I've been collecting parts from all over to make my "ultimate plinker", and I have a nice RRA varminter to compare against.
I have something to shoot in the day, and something to monkey with in the evening.
All in all, shooting is a cheap hobby. Compare it to buying a boat, or motorcycle, or even golf. See what the market is for used golf clubs compared to a used RRA varminter!
It sounds to me like you want a good trigger. Add $100 for the trigger and $100 for the lower receiver, and $100 for shipping, FFL transfer and your time... kits are not really money savers, but are a great learning and hobby deal.
Pete