If you want to purchase a back issue of ST for your Kindle machine (or any device that runs the free Kindle app) you may like to know that it will cost you one dollar. More precisely, 99 cents - that's the lowest price you can actually charge, apparently. Sales of ST for Kindle have been fairly low considering the sheer number of people out there, and I'm not sure if this is because the thing's overpriced or just not that popular. Or some combination of the two. Anyway, if you can buy a copy that's great, if you can recommend ST to a friend that's fab.
Details of how to purchase ST are here.