Talk:Feat of Strength Achievement/@comment-24491781-20150615170228

The way it would cost around 10,000 gems is if you sent the right trains and most profitable in terms of Gold, Cement and Nails to 1 week journey Around The World and then speed it up for 173 gems.

And then just rinse and repeat until you get that whale load of 4,000,000 Cement & Nails and 200,000,000 Gold after spending over 10,000 of your lovely emerald gems