im quite sure the 14.5 will be more cost effective. i ordered my 18" upper in feb with all the bells and whistles (upgraded to 13.2" SAR rail, NiB BCG, got the barrel flutted, went with gunfighter mod 3 charging handle). at that time, they originally came with 12" BAR rail, standard bcg (not sure if it was phosphate or hard chromed bcg), and forged charging handle....so im not sure if the price i paid then would be more or less than what they charge now. private message me if you're leaning more toward the 18" so you can make a better decision as to how much you want to pay. also decide on the purpose of your weapon, if you want something more for cqb or for distance/accuracy. keep in mind you can also get a 14.5 with the LW-50 barrel that the 18" SPR comes standard with. usually, the standard barrels would suffice for any application, but since i was building my 1st AR and was investing some good change in my rifle, i wanted to go with THE BEST that SPIKES has to offer, and that LW-50 barrel is just that.