Or even just a couple dollars. What I typically do is have a few wish lists for various product categories, and I’ve got one called “Free Ship.” In there I have a few items that are really cheap, ranging from $1 to $3. The whole point being, if you’re not on Amazon Prime and you’re just $1 to $3 away from getting free shipping, you pick one of these items to bump up above $25 USD for free shipping.
Of course, it’s all about availability of the item. Some you’ll save and then discover some months or even a year later that the item is no longer available. Periodically you may have to update your list.
Anyway, if you’re only $1 away? Buy some Zebra erasers. You get a pack of 7 for just a buck!