Well buying one ticket is the smartest thing to do, of course if we forget about buying 0 tickets or a negative amount of them (lol, you get money but you have a small chance of paying 15.5 million, sucker !).
If you buy a second ticket the amount of gold you pay is doubled but your chances are a little less than doubled.
Just do some speculation, what will be the next lottery prize.. 50 million or something?
Geez, it's unstoppable now..
Rejoice, if the next lottery prize is 50M, that means ~10M gold vanished.