If you look at the top right corner I can use Turkish Lira in slot games even though my main balance is BUSD. So this is just an exchange of 1-2 minutes. The reason why I choose Turkish Lira from the bottom left corner is that I can play feature game cheaper. (You can buy feature for only 100 TRY. This equals to less than 4 dollars.)
Well actually anyone can change their preferred currentcy on the bottom left corner of the slot window. I've tried this like minutes ago and yeah using TRY is way cheaper compared to other currency in bonus buy. Obviously you get less amount from winning as well but heck $5 bonus buy is a good amount to spend some time on slots