Desperate times call for desperate actions

Given the state of the economy I have launched a serious mark-down strategy with basic white t-shirts. This has increased business, but at what cost? Shipping cost are restrictive because the cheaper the shirts get the more expensive the shipping cost look as a percentage compared to each tshirt. They don't get any lighter the more shirts people buy, but higher weights do get cheaper and easier to ship. With the inexpensive business model I can't offer free shipping, so I've capped the shipping cost off at $75 as a maximum.