Can someone please explain the difference between a Sporter model and the SP1 model AR?

From my understanding the SP1 model is Vietnam era and has the triangular shaped forearm.

Does one carry a higher price then the other?

Is one more desireable then the other?

The Sporter and the SP1 are one in the same. The Sporter ll was the designation given to the AR15a2.

The sp1 brand new in the box (if you could find one) has the greatist collector value. But a preban ar152 is generally worth and sought after  becaues of the upgrades that was made to it. if that makes any since.

There SP1 was produced for a long time at least 20 years. Therefore many many more of them are available than the pre ban SP2's. The Pre ban SP2's bring a higher price because there are fewer of them out there. I like the SP1 much more than the SP2. Other than the rate of twist in the SP2's, I don't see great advantages in the upgrades. That includes the sights. I'm not a target shooter, I set BSZ and leave it alone. The SP1 sights were fine for that application.

The Colt sporters were built for civilians. The SP1 was manufactured from 1964 to 1985. The SP2 was manufactured from 1984 to current. The SP1 had two different models a 6000 & 6001. The 6000 is worth 1450 NIB and 1100 in excellent shape. The 6001 has a collapsible stock it's value is 2000 NIB & 1800 in excellent condition.