When I open some free gifts. and I open all at the same time, The other chest could have lets say 100 coins for 1 chest. But when I open all "Lets say" 50 boxes. The price would only go up to like 350 coins. Is it supposed to do that?

It is all randm prizes . you might get more coins if you open them one at a time some days. rather than opening them all at once . but it is all random .. It sometimes seems like I get more for opening them one at a time . but it is jsut chance . you can open them one at a time if you want to .