I just ordered some 45acp Federal HST from Streicher's for $18 for a box of 50 rounds. Usually the shipping can get you when ordering ammo but there is a coupon code on the site for free shipping for fathers day. There was a Ammo shipping surcharge af 60 cents a box.
I usually pay about $20 locally for a box of 20 of the regular HS. This gets really expensive when function checking a new gun.
They also seem to have pretty good prices on Speer ammo also, but I have not priced the speer ammo much.
http://www.streichers.com/Default.aspx