I can only +1 that, since i have succeeded multiple investigations. Dont upload wall of text in the skype, printscreen only the essential parts, where he says thank you, yes im satisfied, where he says yes i sent you money, paypal addresses exchange and ofc how he aproaches you in the beggining.
If the investigator wont be a dumb brick, it will be enough for you to hold your hard work earned money. Good luck guys.