IMO a higher end bike - and not saying this as a bikesnob, just because the $:Benefit isn't there doing this with a $300 bike plus tolerances are tighter with better parts - should have all or most of the following things checked and lubed:
-BB cups in frame
-QR Skewers/maxles/QR15/X12 etc
-Seatpost (friction compound for instead for carbon items)
-Exposed mating surfaces of headset parts (e.g. most stuff above the top cup, crown race, upper race)
-Chain (lube, clean, lube, clean!)
-Handlebar (friction compound or very light greasing)
The following should be checked for tightness and torqued, loctited or both
-Stem and seat clamp bolts
-Brake mount bolts
-Pivot point clamp bolts
Gear and (if fitted) brake cables should be pulled tight so ferrules seat properly onto housings and into frame.
Thats a short list, if doing a frame up build you'd probably face BB, chase BB, face headset and brake mounts, swish some Lanolin protectant around in the frame of a steel bike etc.
If you do all this you significantly minimise the amount of things coming back in the short term with mystery creaks, rattles in the rear suspension, suddenly out of 'tune' gears etc.
Bike works well out of the box and doesn't require servicing 7 days later due to all the stuff thats moved against each other/opened up tolerance/absorbed moisture/lube dried out, happy customer. In my experience, faith in a shop's ability to nail the build and preservice helps a lot in garnering return business and customer confidence in accessory/replacement/upgrade suggestions.