Bhutan was god damn amazing. Spent about 5 days there. It is basically the land that time forgot. You feel as if you stepped back in time a few centuries. In my travels, I found that they only got television back in 1999. Marijuana grows absolutely everywhere (called weed for a reason). The locals had absolutely no idea it could be used as a drug until getting television in '99. Prior to this, they used to feed it to their pigs to make them lazy and fatten them up.
Not sure if things have changed since my trip in 2012, but the rules are pretty black and white for western tourism. It was something like $250 per day (set fee by the Bhutan government). This will include your tour guide, driver, lodging, food, etc. This was non-negotiable and you are forbidden to travel around on your own. Despite this, it was absolutely well worth it.
*Edit* Same travel fees:
Money and costs in Bhutan - Lonely Planet
I tacked this 5 day side trip on to my Nepal trip and honestly it was the highlight of both. Make sure you make the long trek up to Tiger's Nest. Absolutely stunning to look at and I think it's the highlight of the entire trip. Be ready for a fairly steep ~1km ascent on foot.
Paro Taktsang - Wikipedia, the free encyclopedia
Not sure how you are with flying, but the landing into Paro is god damn interesting. Pretty sure there are YouTube clips of it. Can't fly big commercial airliners in because it is nestled deep in the himilayas. You basically come in slaloming mountain peaks and make a steep descent landing. Pretty nervewracking, but all part of the Bhutan experience!
