At GoDaddy it's about 75-78 days approx. You really should consider transfering it before it expires because there is no guarantee it will be available to re-register, because it may never drop. But instead may be bought by somebody else.
I wouldn't risk it for the few dollars you'd safe, unless it's a really really unattractive name that you know no one will pick up for "tasting" in the grace period. I actually expect a lot of these domain tasters will be using an automated script to be honest, would be trivial. So even unattractive domains could be snapped up.