I get asked this all the time. Here are some brief observations on the subject.
First you need to be clear that the motorcycle itself depreciates in value, requires servicing or spare parts, and may even come back damaged.
The costs consist essentially of the following items:
Transport costs: shipping the motorcycle by sea or air freight, or your own transport with a trailer. For air freight budget between DM 1,000 and DM 3,000 depending on the destination. South America, Australia, etc. are expensive; the USA and Canada can start with a "1". For Vancouver (Canada west coast) I paid DM 1,290 return in the same plane (Wardair) in 1989. Sea freight is usually cheaper but more stressful (risk of theft, schedule inaccuracies, damage risk in ports, and the tedious paperwork at the destination). I paid DM 560 one way to India (Bombay) and DM 800 one way to Thailand (Bangkok). Return shipping must usually be arranged locally, but there are freight agents everywhere, and costs are similar to the outward journey.
Equipment costs: varies greatly depending on what you already have. Anyone with a high-quality lightweight camping set can save the roughly DM 1,000 required here (tent approx. DM 400, sleeping bag DM 300, mat DM 100, stove and miscellaneous approx. DM 200). Then there is the luggage system: small Ortlieb bags start at around DM 50; high-quality aluminium panniers plus carrier can easily exceed DM 1,000.
Flights: you obviously have to get there yourself, either by flying, driving with a trailer, or riding to the destination.
Tyres, fuel, oil: everyone can calculate this for themselves. In Algeria or the USA fuel costs a fraction of what it does at home. Arrive on worn tyres, fit good off-road tyres locally (anything else is a real waste).
Living costs: always much cheaper in the developing world than at home; camping is often not worth it when you can get a proper bed for DM 3. In India, for example, you can live quite well on DM 100 a week (big-city luxury hotels aside).
Here are some concrete figures from my trips (including everything – transport, flights, and fuel): 6 weeks India DM 3,500; 6 weeks Thailand/Burma DM 4,000; 7 weeks USA/Mexico/Canada/Alaska DM 5,000 (21,000 km!); 3 weeks Nepal/Tibet DM 2,500 (last-minute flight, hired bike); 6 weeks Australia/Tasmania DM 5,000 (including the resale loss on the XT600 bought there); 5 weeks Morocco and Spain with trailer to Spain DM 3,000. I have not included equipment or servicing costs as I already own everything and partly do my own maintenance.
Simple Africa trips are comparatively cheaper: you can ride there under your own power, fuel and living costs are low, so you can manage well for under DM 2,000. My Tunisia tour in 1985 cost only DM 800.
