Well if he wants he will find out that you're hunting that domain. I would put a backorder, mostly if there are several brokers interested in it. I'm not sure if he gets any "ping" that you want to buy it though...
Currently the whois records show that it expired as of 27 Jan 2011 (but is not yet available).
Off the top of my head they'll still have the chance to renew for about 30-40 days or so, I believe it varies between registrars, and then its another 30-40 days before being released therefore the minimum is about 70 days and up to about 90 days.
Somewhere after 3rd/4th April up until 23rd/24th April.
You have to evaluate your own risk as to whether you want to place a backorder and almost be sure of getting it if, as you feel it's not worth anything to someone else, or to wait for it to drop at a regular price.
I have to say that some of these domainers are complete nutters with their values. I recently bought three identical keyword names in .co.uk, .de and .us for between USD 300-500 each, the guy who owns the .in wants USD 80,000.00!