$2500-$3000 for thermal scope and sub $1000 for monocular. I see some Thermals for cheaper that are 384 resolution so I could go with something cheaper than $2500. I know for sure I want a thermal monocular just to see what is all out there. Seems that plenty of people use night vision after spotting with a thermal. Just trying to get some actual real world use advice. If I could be just fine with a night vision scope, that won't bother me none. But IR light apparently isn't the best with thick brush and short shooting distances???
I am quoting somebody else for this, but I really like the saying. When it comes to night hunting, digital night vision is for the more casual hunters. Thermal is for the guys who are getting serious. What does that mean? Digital NV has a lot more issues than hunting with thermal, even 384 resolution. I am not a big proponent of 256k thermal. It can work, but can also be a struggle.
The issue with digital night vision and sometimes with even Gen III stuff is that you will need an IR illuminator and that will have issues with reflectivity, aka IR bloom, aka photonic barriers....basically light (reflected or otherwise) that whites out your scope. This makes hunting in the woods or in brushy areas much more difficult. It works best for wide open, low brush fields, feeders out in the open, senderos, etc.
For $3k for a rifle scope, you can get a variety of 384 scopes. Right now I am testing the Rix Storm S3 that retails for $1800 and that would give you 2000 for a spotter or $600-800 for a DNV sight and $1200-1400 for a thermal spotter. I am not saying that a Storm S3 is the scope for you, but am using it as an example of an inexpensive 384 resolution thermal sight that would do well in your budget. I work for Rix and so I am going to tell you about their stuff, but I also am a hunter and know that everyone has different likes and dislikes.
Based on what you described, I think my idealish setup might be something like a Storm S3 for $1800 and an AGM Taipan 25-384 for $1600 and the rest can go for taxes and ammo. You could do very well with this sort of combination for your budget.
I am using a Rix Pocket K2 spotter that is only $500 and 256 resolution. At 100 yards, some small animals (skunks, rabbits, armadillos) can literally disappear and reappear between the pixels. You can spot things, but often you won't know what they are, or you can only guess because the resolution just isn't there. I would strive to get something with at least 320/384 resolution unless you are just hunting 100 yards and less. Otherwise, every time you see a thermal signature in the distance, you will have to raise up your rifle to identify it. That can get bothersome. I much prefer not waving my rifle around every time I need to identify something. However, I hunted a few years with fair low resolution digital night vision and a 320 resolution 9 (NINE!) Hz little FLIR where the pair did me well, but both aspects were problematic. You can make it work.
If you just have a feeder set up at 75-100 yards or are just killing critters around the house/barnyard and want the cheapest functional setup, get a $500 or 600 digital night vision scope and maybe an inexpensive thermal.