Come to think of it, what's the cheapest soundcard ASIO supports?
This is 6 months old, but it gives ya an idea: http://groups.google.com/groups?hl=en&selm=%25n0T6.253%24bZ6.32947%40new...
More recent: http://groups.google.com/groups?hl=en&selm=3C4D6B57.D79FFD1B%40xxx.xxx