Well you are new with no reputation here which is probably why the buyer wants to pay only half in advance. Once you have build trust everyone will pay you full in advance.
Anyway I shouldn't say more because it's not my thread nor I'm looking to buy anything. GLWS
p.s. pics with PC lights on and monitor showing
display tests with your name/date paper in front would do wonders. Saves you the headache of things turning out bad if a components gets damaged during shipping (if/when you go that route).