Dread, I'm not a coffee drinker, but I got one of those for my dad last year. I think the main differences are the cheapest ones are fairly plain in that you get your cup of water, dump it in, put in the k-cup, put the cup underneath and press the button. As you go up in price you have the ability fill a reservior that can do multiple cups before refilling, set auto timers to have the cup made for you every morning, different temperatures, different sizes of cups, etc. The higher price, the more of those features you get. Also they make some different colors and different asthetics cost more too.
EDIT: additionally it isn't just Keurig that makes them anymore. Several companies now make K-cup coffee makers. They all work the same way, just different companies, styles, features. All use the disposable, single serve k-cups though.
Excellent job on the ring as well. I'm sure she is proud of her new shiny posession!
