i tried sending about $50 to someone using the browser extension of MEW on firefox. i pick the fast transaction that the MEW set for users and the gas is about $1.10, but why do i get the error " Warning! Error encountered during contract execution [Out of gas] "?
The problem was already mentioned, out of gas.
Since you are looking at dollar figures, there might be something wrong with your calculation. How much ETH balance do you have so we can sort things out?
As always, you need to have an extra amount and not an exact one to make sure the process will go through.