It really depends on the definition of "high end" card. The newest fastest card may not be the most profitable for mining. Not only do you have to consider breakeven time (the longer it gets, the higher the difficulty), you also have to consider the running cost in terms of BTC/watt.

For those who already have a decent btc/watt card, it would likely make sense to mine since you already have the card. More so if the power in your area is cheaper.

Like in my case, since I keep my system running all the time even before mining, so my only consideration is btc/watt which fortunately is higher than my cost/watt even if the value of btc falls significantly. So for somebody like me who already bought the card for the purpose of gaming, any potential income makes it worthwhile... especially since there's not much effort involved in starting a miner and leaving it to run

Pending review of how much btc I made over a week, I might even be able to pay off enough of a second card to enhance my gaming experience.