Thanks, Vladimir. After finding this comparison of ASICs and video cards, I see what you mean:

https://en.bitcoin.it/wiki/Mining_hardware_comparison

EDIT: I'm sure most folks here have seen this, but for others who stumble onto this thread, this is worth reading:

Miner problem: big changes are coming for Bitcoin's working class
http://www.theverge.com/2012/11/16/3649784/bitcoin-mining-asics-block-reward-change