I just bought all USGI parts to finish my EBR about an hour before the Bula parts kits went up for sale on the M14 forum, but I got a brand new old stock TRW oprod (not a retab) out of the deal, so I still made out. Really wanted to go ALL Bula on the EBR, but I only ended up paying about $80 more for all USGI parts that I didn't have...minus a brake which I still have to get...so maybe $150 or so more than Bula.
$851 for Bula XM21 receiver #52 transferred to me at Pullman Arms (included gas to and from)
$325 for Mod 0 Sage Chassis from M14 forum and 5 screw upper handguard from GunBroker to accommodate my Medium weight barrel (have secret plans for the 6 screw top cover already though!)
$625 for USGI parts
Puts me at about $1801 for an EBR XM21 sans optic. I'd say I did pretty good, but my savings account feels like a Tijuana hooker on Seis de Mayo.