Thank you Styxfan, I just found this board and I tried searching for a thread about this but didn't have much luck. I did find this quote on a travel site ...Transportation-Includes everything from air packages to taxi fares, whether purchased at home or abroad. ... . $750-$1,500 is a rough range for a medium distance round-trip with a month of "getting around." $2,000-$3,500 should get you around the world in the Eurasian corridor with moderate surface transit for two to four months. You'll get more transit over more time for $4,000-$6,000 and/or you'll be able to add Africa and the South Seas to around-the-world journey...
Per Diem (daily allowance)-For me, this primarily means food, shelter, admissions, and beer. ... A budget per diem might be $10-$30 ($300-$1,000 per month) in the developing world, $25-$60 ($750-$2,000 per month) in developed nations.