I've already round filed the mags, but I believe either American Rifleman, Shooting Illustrated or the weekly NRA email had an article about it last week.
If you didn't get the mag, you should have. Join here:
I have a Vortex 1000 that I picked up for hunting right before the 1500 came out. We use a Leica for or long range pursuits. My buddy picked up one of the Sigs to hunt with. All 3 of these are within 1-2' of each other at 1K.
I purchased the Vortex primarily because it had a tripod mount. The Sig you have to buy an optional sleeve for. This was primarily in case the Leica failed for some reason. We use the LRF to confirm what we get measuring with the reticle. When you mount it to keep it steady some of those 1/2 the distance issues go away. I know I have ranged deer (not so reflective) at 800 yards with my Vortex. BTW we sold the Leica and bought a LabRadar.
If you can still find the Vortex 1000 it seems like it is only about $50 more than your limit. The only thing I am not fond of is how many button pushes it takes to range when it is asleep.
if you are former or active Military or Active or retired LE Vortex offers a 40% discount on all their products so that would put you well with in budget