about the money; well I think it depends on what you are willing to spent first of all. And number two, the 'variabel' costs are different for everyone ( got a bike? prepared bike? got a tent? or do you need to buy all this? etc)
My TOTAL budget is around 10K, in Euro's that is (approx 6 months travelling). But next time I don't have to buy and prepare a bike, panniers, tent, sleeping bag, stove etc etc.
Hope it's enough for me.... But to me it's a sport to find everything as cheap as possible (bike parts).