IMHO he won't return. He will choose Arabian money.
Various new reports have him as wanting to go back to Barca for 25m a year. I think that's pretty admirable considering he is being offered around 400m a year in Saudi.
He obviously cares about money, most people on the planet do, but he is far from the green eyed monster some people like to portray him as.
Actually, that could be said of a lot of our players. Many of them have foregone money and made deferrals that simply haven't happened at other clubs and most here would not have agreed to themselves. Overall, I think as fans we have been rather unfair on them in this regard, always taking the most negative of intentions.
Make no mistake, if Messi doesn't end up here, it will be on the club and not him.