I have seen more than a couple comments about PayPal shopping carts not allowing specification of shipping charges on a per-item basis, and although that was true, that problem has been remedied - it can be done with very little hassle. You do have to change a setting in your setup on PayPal's site - same place where you define your flat rate or percentage-based shipping charges. I believe the option is 'Allow transaction shipping rates to override standard shipping charges..' or something like that.
To use this option, you add one or two input tags to your shopping cart - shipping and shipping2. If you want to charge $x shipping for the first one, and $y for each additional, you would use the following code whithin your cart: <INPUT type="hidden" name="shipping" value="$x"> <INPUT type="hidden" name="shipping2" value="$y">
If you want to charge $x shipping whether the customer orders 1 or 10, just use the first one (shipping).
I really love this feature because it allows much greater control over what the customer pays for shipping.for everything else.