What is a second hand car payment to you? My NV setup cost more than my truck, but my truck is a functional POS. You can look on forums like AR15dotcom and see some PVS14s that are around 2000. Lower than that you may be looking at a PVS7 which comes with its own disadvantages. Keep in mind that is just the cost of the unit itself. You need something to mount it to and mount it with, which are additional costs. Then you get into setting up a weapon to utilize NV well, and there are additional costs.
Unfortunately NVDs/NODs are just one of those things that are hard to cheap out on and get good function from. But it really depends on your use. If you are just wanting to look at things in the dark, maybe something like a Sionyx digital device may be good enough for you.