How much electrical do you have?
You can buy NEW Brazilian in that power range for that money. Buy on Amazon/eBay and buy 3rd party warranty and you won't have to worry about anything. If you want reliable, you should be setting your sights on low to mid 700$ range (used) proven 5K boards. American Bass, Crescendo, DC, DD, etc.
Oh, and amp-lab in Maine (google them) had a Team Cactus 7K refurbed for a very fair price recently. Not sure if it's still there but that's a pretty beast 7K.