BTC are high right now and I even bought myself a decent rig because of this.
But it is of course possible that the BTC comes down. At what price is mining no longer profitable? What are your thoughts on this? Have you concidered this when you started? Looking for some opinions before I go and buy more stuff.
It will take quite a lot to make mining bitcoins not profitable:
First time it will be unprofitable it when the bubble crashes and BTC are worth ≈$0.1 each, but that will be due to the "despair" part of a bubble, it will go back to about $0.5 each a few weeks after that and slowly climb to $5 after a year. The second time will be when cost of KW/hr becomes more than you make (on average) an hour, which should be about a year for current generation hardware.