The sim cards should be free, at least if you go to a corporate store. You can also get customer care to ship you one, if you care to wait, or if you do want to pay for overnight shipping (maybe a nice rep can even waive that, like I used to.)
Just to let you know, if you move from a 4G phone to a 3G phone, the LTE sim card in your 4G phone will become "retired" in VZW's system and will never work again. So, if you move back to a 4G phone, you'll need to get a new sim card. Its inconvenient, but just a heads up.