on the other hand, $.70 is more than you would have had if you let it drop. Other than some donations/freebies, I don't think I've ever sold for less than $1, just because the effort to do so isn't worth the small change.
Another way to potentially recover from bad buys if you have good renewal pricing is to sell with a renewal. For example, if your price is $6.95, and you sell for $9.95, you've made $3 instead of $1, and the other person may just have bought for what they normally pay for a new registration or what they'd pay to renew an expiring one they purchased for $1.