12 weeks when I was at uni, through South America. I couldn't tell you what that cost, but it was shoestring stuff. A few years ago I did an 8 week road trip that crossed a decent portion of the earth. I think from memory that cost about $15k including the car (for each of us). On that trip we stayed in everything from camping by the side of roads to stinking hot hostels to 4-5 star hotels. I wouldn't want to do that every year though, that sort of constant moving gets very tiring.