Yes, I am paying about $3 per round as well for 12ga. sabots. There is no reason why you should have to buy the expensive rounds all the time. The only real difference I know of is the lead sabots leave more in the barrel to clean. I see no real difference in performance, and I would suggest you try one shot sighting. It will save you a lot of ammo. It works just fine, and you already have the lead sled I believe. Aim perfectly at the crosshairs with the gun fixed (sand bagged, or sled) fire 1 shot. resight exactly on the cross hairs again. with the gun sand bagged, or sledded, adjust the scope only, to the bullet hole. All conditions matched, you are on target at that range. Should save you some serious cash. I have the Mossberg 500 Sabot, and I use this method.
The only real difference between a good tracker and a bad tracker is observation. All the same data is present for both. The rest is understanding what you are seeing.