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I believe the Ninox has been discontinued. Regardless, I think the Spark Core is about the only Gen 1 to recommend, it would likely be the best performing gen 1. But I believe they are bumping right up on your price limit.
This is truth. A good gen 2 unit will do alright, but your best bet truly is to save up for gen 3. Gen 1 gets you started, but it really is not a great solution.
If you really, really want NV, and $1k is your cap, the Spark is the way to go. If you want the sad truth, it is to save up until you can afford something better, and not take the hit on trying to sell your gen 1 down the road.