So guys , i've tried this method with shakatu
And it worked 100%

So the method is you read what shakatu said above his head , every sentence he said means each type of gears we should pull

And buy 10 singles first
Then hit the bulk purchase

I've tried with 5k gold coin and i got 6 gold gears with only 2.800 gold coin

Watch below to see the magic works

I prefer quick glances not a 9 minute video that can be shown in 2 seconds, so here's for anyone else that wants a cheat sheet.