I picked up a used ATN NVM14 Monocular for $1,100 and when paired with an IR Illuminator, it's like green daylight, pretty awesome, putting both on a helmet. I still want a Thermal monocular I can also mount on a rifle.
Everyone's definition of what breaks the bank is very different, what are you looking to spend?
ATN OTS 336-50mm 9hz Monocular
ATN NVM14 NV Monocular