http://www.joeboboutfitters.com/Smith_and_Wesson_M_P15_22_FDE_22_Long_Rifle_p/gun-811035.htm
I have one an absolute blast to shoot
Barking Irons had them under $500, Grab a gun had them at a decent price also. It is a well made .22 IMO. $600 is a little high, even for the magpul version. Now if it was the performance center model, maybe.