What is the benefits and costs for SBY and his staff to lower prices of basic or strategic commodities?
The benefits are clear. He will gain popularity and votes to win the election once again. If he looses, these benefits are gone, but so are the costs.
The costs, depend. Whether he wins or loses, the monetary cost will not matter much -- it's taxpayers money, not his. The bigger cost however, should he win, would be a hardship to his administration. Lowering prices now with support of subsidies is akin to set the time bomb for the next administration. Whoever wins will face a tough job managing the budget as the economy starts to recover probably in the middle of the period.
Well, maybe I overstate the problem for SBY. Note that he can't run for the third time. So the burden, even if he wins, would be less heavy than if he would have a third opportunity. But what does this imply? Yes, the incentive for SBY to run policies or programs that are economically sound now is small. He might as well trade them for more populist, vote getting ones. A clear advantageous position, to his rivals dismay.