In that budget I would suggest the Pulsar N550A or the Sightmark Photon XT. Feel free to shoot me a PM if you have any questions.
^^^^This is your guy right here. He'll fix you up with a Photon. For the money ($500ish) it can't be beat.
In your price range you'll find a lot of junk (no offense intended) but there are some good options. Night vision is expensive any way you look at it. If you can save a little longer you could get a gen 3 PVS-7 or lower level PVS-14 for somewhere around 1500 or so used. You would then need an IR laser like a Lasermax to do the shooting. The advantage here is you're using the 7 or 14 to navigate as well as shoot.
I dropped 7 pigs last night on our place using this configuration.
Night Vision & Thermal Sales
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