Just speculation here.
Sun/Weather: he was gutted last year when he learnt that we didnt have a winter break, so he could not go on holiday for 2 weeks, European market was shut so he couldnt go anywhere over here when the window had shut (team in Turkey wanted him seemingly but he may not have fancied Turkey), UAE team came in for him, who only play 22 games in a season I believe, and it is hot over there in the winter but not 44degrees, probably closer to 25-30 degrees (better than our summers).
**** league: Going to turn this on its head, he was in a hard league with a team that didnt exactly set the world alight, and he was part of the problem (not all of it but still a part), so go to a **** league where he very well may look world class compared to the rest, win them the league (they finished 3rd from bottom last season) get noticed, get a move back to Europe with some confidence and sun on his back. Its a small world, scouts over there, and easy enough to get videos of the matches.
Money: honestly not sure about this, he signed the contract just last year, if he wasnt happy with the amount, he shouldnt have signed the damn thing, if its Wickham or ji is on more per week (its possible) then surely he should have has clauses in his contract IE I have to get payed the same as the top earner, or even, I have to get payed the same as another striker, if they are on more than me.