FWIW this week's Economist seemed to think that the situation in Sri Lanka is deteriorating, so it might be useful to have a thought-out Plan B in your pocket.
There have been some discussions here in the past month or two about cheap starting places, plus of course the excellent spread-sheet with prices from everywhere. One important element (besides the cost of getting there) is actually finding a GSA who'll sell you a ticket in Timbuktu - surprisingly difficult in many Timbuktus.