It should cost around $200 for a skilled tech to assemble your guitar. That may seem like a lot but don't forget, there is a lot of work to do in assembling a guitar properly. Sure, you can hack-job it together and get a guitar that plays about as good as an Affinity Strat and tunes about the same, or you can take your beautiful new parts to someone who knows what they're doing and will turn that collection of parts into a seriously nice guitar.
1) Check the neck for proper fitment to the body.
2) Locate and drill the holes for mounting the neck.
3) Position the tuners and drill the mounting holes.
4) Locate and install string trees.
5) Shim the neck pocket if necessary to achieve the proper neck angle both side to side, as well as up and down.
6) Level the frets and polish them to a sparkling sheen that will guarantee clean fretting and buzzless playing!
7) Locate pickguard and drill screw holes to mount it. Or drill holes for pickup bezels, and mount them.
8) Install output jack
9) Wire the guitar properly so it doesn't hum or crackle.
10) Install the bridge,
11) File the nut slots and set up the action for slick playing.
12) Adjust the truss rod for a slight bow/relief to insure true, clear notes.
13) Set the intonation for perfect tuning.
14) Adjust the pickup height for balanced output and maximum tone.
15) Drill holes for strap buttons and install them.
There's a lot of work to do.
A properly assembled guitar will play and sound terrific. If you're not thoroughly experienced you try doing it yourself but the results may leave something to be desired.
The best advice I can give anyone is: Buy an $99 Squier Strat and take it apart completely right down to the last nut and bolt and wire. If you can re-assemble it into a great playing guitar that sounds decent, (as good as the crappy pickups will allow), then you're ready to assemble a Warmoth guitar effectively.
Otherwise, $200 should get it assembled real well. And it's worth it!