Welcome to FT!

"Cheapest" is a misleading term. The base price is one thing, the taxes, service charges and uneven fuel surcharges are another, and of course the cost of accessing the start point, whether measured in dollars/euros/whatever or in spendable FF miles, is another, and the on-site costs at the origin point (hotels or other subsistence expenses while waiting for your first flight etc.) is yet another.

Currency fluctuations are increasingly a big issue. Last time I looked (and it's a moving target on a daily basis) South Africa was cheaper for D-class OWEs than Mauritius - if one is translating ZAR or MUR to USD. In Asia, last time I looked, Manila was the cheapest place, with yen v. dollar exchanges having knocked Japan out of the top spot. I'll believe the Sri Lanka prices when somebody gets ticketed. My personal belief is that it's a case of not updating tariffs on the part of CX or RJ.

In Europe, Sweden seems to have lost "first place" to Gibraltar by a few pounds/dollars. Now that IB serves GIB, it can be a decent starting place if one is looking at moving on to North or South America directly; unfortunately BA still goes to LGW from GIB, so any longhaul options after the first segment are constrained, or else one needs to burn a segment due to the LGW-LHR connection problem. (And since AA is leaving LGW, no North America transits now possible except on BA to the Caribbean.)

All part of the jigsaw puzzle; love it or hate it.