A brand new Alexi-200 Right-Handed guitar customized with a Blackout pickup...

Any other modifications you do to jack up a price? I get good discounts and I know how to handle guitars...

Guitar New is 429
Pickup new is ~100

I'm not looking for an opinion on what you guys think of the guitar itself, just a simple question, what is a reasonable price for that?
Bridge swap to something better? Better wires/pots? Coat the inside with copper shielding? Say that you got it "proffesionaly" set up (see; Proffesional is subjective. Hah), new strings, new battery, level frets?

I really don't know. Since the total you spent on it so far is about 530 $ I would attempt to sell it for 430-460$. If that is a no go simply lower the price till it sells.

Best of luck mate, hopefully I wasn't wrong about my advice haha.
Blackstar HT-5

Agile AL-2000 with Chrome Hardware
I think your gonna find this is a money losing thing. A 429$ guitar with a 100$ pickup wont mean you will get 529 for it. Check most of the threads on this site about buying guitars. Most are how can I beat the music store up for a lower price or free stuff. And where is the cheapest place to buy a guitar. The store near me is barely hanging on with the economy the way it is.