Hi there!
There are many different models of these, with the most basic one being "you fill your coffee cup with water, dump the water in the top of the machine, put in a pod, press start, the water from the top comes out the bottom as coffee." This is the most basic and lowest cost model. I've seen them around $80, but I haven't shopped for them in a while.
Then there are all the models where there is a water reservoir, in differing sizes. These are more for an office or for a home where a lot of coffee is drunk. The downside to this model is you're supposed to leave it plugged in, which is an energy vampire/phantom load, not to mention that if you don't use it enough, the water will get old inside.
My husband has one of the reservoir ones, because "it's cool"... These go from $99 (on good sale) up to $200+ (for the fancy schmancy office-sized ones that spit out the pods on their own and collect them in an internal garbage bin...)
You may be able to get a better price by going through the Black Friday ads and also considering Bed, Bath, and Beyond (read the fine print, they exclude a ALOT of things from their coupon deals.)
Once you have the derned thing, there is the question of the pods. They are price-y, but less so than buying cup after cup of Starbucks (buying in bulk you can get them for $.50-$.75 a pod). Any model you buy will come with a small sample of different pods. The tea and cocoa ones make me laugh, because I can get teabags and cocoa mix wayyy cheaper than. A$.50 per serving.... There is a K-cup swap thread here on the DIS, I think, where you might be able to trade ones you don't want. Or if you're sure you're getting one for DH for Christmas, you can suggest to relatives that they get him pods to go with it (and/or mention that you'll take their sunday coupons for k-cups if they don't want them)... You *DON'T* need the fancy carousel that displays all your pods... that's more of an office-coffee-room thing. Most families only keep a few varieties anyway, so save your counter space and just keep em in the box in the pantry.
At some point, you'll consider buying the "My K-cup" refillable filter... I've only met one person who didn't HATE theirs and throw it away... he said the secret was you have to grind the coffee REALLY fine to get it to work, but that he loves his. FWIW...
So, good luck in your adventure... remember in the end it IS cheaper than going out for coffee, and MAY be less wasteful than making a pot or half-pot every morning and tossing most of it... remembering that will make it hurt a little less to pay so much for a derned COFFEE POT!!!