We too buy 10 packs of 10 small satchels @ $0.15 each.....i.e. $15 for 100.

We operate from a small regional town so we can never receive a discount for "same major city" however most of our items are posted to major cities so we pay $7.52 postage (band 3) + $0.15 (small satchel) = $7.67.  To rural areas $8.68 + $0.15 = $8.83

New prices for us go to $7.69 + $0.15 = $7.84 & rural $8.88 + $0.15 = $9.03  Increase 2.2% for both.

Not much saving when sending to rural areas however it helps to keep us on band 3 & sometimes band 4 in busy periods.