Ebay is your second best option. I always start my products at $0.99. 90% of the the time I get $100-$200 profit from what I originally purchased. I'm selling my 6 Plus to my friend for $1,200 compared to the 128GB full price of $1,026
Does your friend have a mental disability? If so, shame on you. If not, tell him I have a mint 5S for sale.