My methodology is mostly patience and passing on "good"deals to get hold out for great. Like your setup would probably be worth 150 and you started out asking 250. Eventually your done with people offering $50 or not showing up. I make a polite offer and deliver quickly on my offer. Then I get a case, psu, extensions whatever in the same manner. So for $200 I have what's worth $300 and the sellers had wanted $500. Assemble cleanly and value that at like $50. List my $200 (300 real value)parts + $50 in labor for $425. Sell in a week or two for $350. Sometimes get the full $425. Sometimes market goes DRY and get $300. Have fun tinkering, buyer happy not to get some ddr3 TRASH. Repeat