The most fundamental factor that will determine the fare is the time of year you take your first flight as almost all fares are based on your first departure date.
Currently, the UK is just about the cheapest place to start your trip from and most tickets are now common-rated in price from Manchester as well as from London airports, like Heathrow and Gatwick.
What is the cheapest month to start a RTW trip?
Here is a guide to the typical seasons. (These do vary from time to time and from airline to airline).
|May||Very low||Check prices|
|June||Very low||Check prices|
|December||Very high||Check prices|
So this means that no matter what route you end up taking the cheapest single way to knock hundreds of pounds off your airfare is to leave at another time.
This obviously isn't always possible as you may want to be in certain areas at certain times for things like best trekking season, avoiding monsoons, carnivals etc. but if price is an issue you must learn to be flexible to save money.