Then you've dropped too low. You certainly don't do it for $1. But I've found that whenever there are other companies with ideological bents (like anti-IE6) I can almost certainly always crush them economically and with respect to quality.
Competing aggressively on price, more often than not, attracts a certain type of client. If you're taking the cheap option now, you'll often fight over every cent going forward and be pretty miserable to work with.
If someone is desperate for work, they might need to make sacrifices to keep busy. I'm not, so I try not to.
It's not all that aggressive. If your intention is to effectively price out technology X (IE6), I can almost always beat your price by a good mile, and I'll make a point of it.
I think you underestimate the huge price differentials for almost no difference in quality. In fact often quote the opposite. I've seen a factor of 5x in price difference in some cases with virtually no difference in portfolio, mockups, or code quality.
That's fine, but I (a hypothetical web designer) am selecting for clients who don't actually care to do IE6 compatibility work, but would try to get it if it were the same price.