Looking to purchase my first thermal in the near future and could use some advice.  It will be used on a AR10 .308. I’d like to stick to under $3K if possible but my absolute max is $4K. I’m currently using a Sightmark Wraith 4K DNV optic. I don’t hunt open fields. I’m shooting down senderos where a feeder is set up around 100 yards down in South Texas. This is mainly for hog hunting. I do like having magnification since my eyesight isn’t the greatest, so being able to zoom in for shot placement is important. Don’t want anything with an internal battery. Any advice would be much appreciated.  These are some that I took a quick look at.  

InfiRay Bolt TL35
Rix Leap L3, L6
Rix Storm S3, S6

Have you looked at the Bering Optics line ? Several options in your price range and they are solid units.

I have not but will.

Check them out. I have the Hogster vibe 35 mm 384 on my AR 10. Good price for a solid thermal. You can use internal batteries or external. If you’re not shooting more than 200 yards, the 384 will do fine. But if you have deep pockets, look for a 640 unit. Good luck.

I have the original Hogster 35 myself and it has served my needs well.  If I was going to purchase a new scope in the same price range I would consider This

AGM Varmint 640 TS35 V1 with LRF from PSA on closeout for 2500 is a smoking deal. 2x mag. 18650 batteries. ADM mount.

That got my attention.  If only it had the ballistics calculation feature like the v2.

Rix L3 will the lrf add on and buy their 5$ ballistic calculator. It is a solid combo that punches way above its weight class. Little tricky to get setup but works great out to 700 yrds or so

Agreed on the calculator.

It's the best deal going IMO. I've had one for about a month.
At 2x base mag the fov is solid. One click on the dial gets you to 4x digi zoom at 320 resolution. It's a solid choice for a mid range,640 with LRF.

What sold me was the LRF. Soon most scopes will have an LRF and it keeps this scope relevant for some time even though it's a V1.

The 384 TS50 v1 varmint for 2k is also something to consider. 4.5x base mag will push you further than the 2x 640 but at the cost of narrow FOV.

For OP needs, the ts35 would work great

The RH25 is hard to beat and from experience hog hunting and deer hunting with it, using it as a clipon in front of a LPVO on 1-2x is excellent. I don't want a thermal being my primary optic.