From the wikipedia article:

From late 2008 to 2010, Bushby spent his time in Mexico for cost reasons and was unable to travel to Russia. This was both because of trouble getting a visa and permits, and because of financial trouble; Bushby lost several of his sponsors due to the 2008 financial crisis. After Bushby secured new sponsors in 2010, the Russian government issued him another visa, and he resumed walking across Russia in the spring of 2011.

So basically he takes breaks, keeps the costs low and has sponsors, but financial troubles are absolutely an issue.