This is what I built some used/ some new.

89 Peugeot Triathlon frame 60$
Wheel set, Vueleta Ailiner 4 rims with suntour front and shimano exage rear 135$
3tt Synthesis stem 30$ Used
Deda Anatomic 215 Bars 30$ used
Sugino xd700 (got off bike I was replacing)
Shimano ultegra SL RD & FD 100$
Shimano Ultegra SL brake set 40$ used
Stronglight A9 40$
Shimano SPD pedals off old bike
Shimano 600 shifters 40$
Vitus 979 fork used 50$

I dont have brake levers, seapost, or saddle but I will figure 100$ for all that. I will prbally get a the nashbar r2 or whatever it is called.

So all together 625$
I looked online for bikes in this price range and I came up with almost all of them using sora parts. I also did not like the bikes I saw in this price range. Of course I have seen some 1500$ bikes on CL for around 600. But still I love my bike I reasearched everything and I am perfetly happy with it. I swear I looked at least 30 or more differant parts for each one part I bought.