I bought an used one (HP Ultirum 6250), you should be able to get it under $1000, closer to $500, but I recommend getting it with the controller so that you kno

I bought an used one (HP Ultirum 6250), you should be able to get it under $1000, closer to $500, but I recommend getting it with the controller so that you know there are no issues. Note that these controllers are made to be mounted inside heavily ventilated rack case, so if you are putting it inside desktop PC I suggest making sure some fan blows on it. It's discouraging that it's so complicated which made me back out of the purchase a few times, but it was well worth it.