2g penalty on combination
There is still a bug going on that started occuring 1 patch ago on PBE and is still on the life patch; sometimes (seems to be when you have less than 10gold) combining 3 champs into 1 will cost an additional 2gold. I'm not sure what triggers it, but it was one of the reasons why I stopped playing PBE last patch.
What happened? well, in 1 occurance I had 0 gold, the round ended, and as soon as the next round started, I got 5gold and bought an evelynn, which combined with 2 others and I ended up with 0 gold, without purchasing another champion OR rerolling.
I hope this can get resolved next patch