I need everyone's help. My uncle is looking to sell his Stag M4. It comes with a A.R.M.s BUIS, EoTech 511 sight, Midwest quad rail, a Tangodown vertical foregrip, and 13 D&H mags. He thinks $1500 is good price. What does everyone think? Thanks for your time and opinions. P.S. I am thinking I should buy this rifle.