Assuming they’re not somehow badly fucked up or stolen (I would be cautious about that after the whole Lamneth debacle...), I would say “fo.”
That being said... for that price, unless it’s just someone who wants to get rid of them that doesn’t really understand what they’re worth, you’re probably talking old tubes that aren’t going to perform as well as a new, modern production unit, almost certainly non-autogated.
That’s assuming they’re not a home-brew unit with mismatched or even lower grade tubes.
However, if they’re complete and properly built, the housing and optics alone are probably worth about $1,200-$1,300 at least edging conservatively, and that’s assuming they don’t come with a mount or battery pack.
In order to use them, you will need either a mount and power supply or a Clip-On Power Supply (COPS - for handheld use). I would forego the USGI aviation components if they’re not included and you’re starting from scratch, and purchase the AB Night Vision Ground Optimized Low Profile Battery Pack (LPBP-GO) and STORM ANVIS mount, which will add about $845 ($495 for the mount, $350 for the battery pack) - the components are a bit pricey, but IMHO well worth it if the device doesn’t already come with some components (usually they do).
Again, assuming they’re not stolen and there’s not something terribly wrong with them, you’re still into a full dual tube setup for less than the cost of a new PVS-14.
The AVS-6 is still one of my all time favorite goggle setups.
~Augee