I have once done PayPal about 900$ and a few Amazon deals worth 1000$-1500$
I am not sure if the above is true or not, and I am not sure of your intentions, however based on your own claims, the most you have been trusted with is $1,500 (note that AGC always sell for fairly decent discounts), and now you are asking to be trusted with ~$3.900 with a very vague timeframe for repayment, and little benefit to the person you are borrowing from (very low interest).
From a cost/benefit/risk perspective, this is not going to be a good deal for anyone considering to lend to you.