I am getting absolutely murdered on shipping costs for books, cds, and records while selling non media items on my store as well. Media mail needs to be added as an option to ship on certain "eligible" products in the cart. I can either set a 36 oz book to 12 oz so it can ship "first-class" so it is near the cost of media mail for US customers but then I am losing my neck internationally by undercharging. USPS just jacked international rates like $5 per lb so this problem is 2 fold worse than last December.
I either have the option of setting a true weight of a book to cover my international shipping costs but way overcharge for domestic by forcing them to purchase Priority when they could have a media mail option at half the cost. Who wants to pay $9 when they could pay like $4 and wait two more days? Everyone knows customers are shipping cost sensitive and I'm just trying to break even on shipping costs but this is getting brutal with no help from Shopify in sight. The experts never answer this problem in the forums.
You may say just create a shipping option called "Media Mail" and set a flat price, but we sell many non-media items. Customers will select cheapest method at checkout even if their order is not eligiable. I can title it MEDIA MAIL (DON"T USE WITH NON-MEDIA ITEMS IN YOUR CART) and they will ignore and check out because it is cheapest option.
I will then get killed when I have to really ship it Priority because a Tee or Sweater can't go in a media mail package and I vastly undercharged them. I'm just trying to break even on shipping but it is crazy this in not an option on Shopify and there seem to be no plans to help out.
Anyone have a solution?
Min from Bespoke Shipping here, if you're interested in using an app, I can help you solve this problem, however please be aware there will be setup costs involved depending on your requirements.
The app can be configured to identify when elegible items are the only items in the cart and show media mail (we can also show the more expensive options if the customer wants to use them) and hide media mail when non elegible items are in the cart.