What has happened to me at least twice, usually on level 7 (the last dungeon on Tier 1), is that I'm heavily right mouse clicking my sword and swamped (solo) by a pile of monsters.
During this fighting I stumble upon a pile of these 5CE cost mecha helper things, which, due to my hammering the right mouse button to swing the sword, against the mob of monsters, means that I notice that I have just wasted 2x 5CE, because the right clicks (I have confirmations set to ENABLED) have agreed to activate these mechas, which I DID NOT want.
So far, this has cost me about 20CE.
What is probably needed, is to improve the user interface, so that mashing the right mouse button, in order to attack with the sword, and/or open boxes/break things, does NOT accidently get your account charged for starting up unwanted mechas at 5CE a pop.
I did spend about 5CE once, to try the paid for mechas, but as others have said, found them to be a waste of energy.
(Off-topic, it should really be 5CE to get a mecha to play with you for the entire set of dungeons, auto recovering after a set period of time (e.g. 15 seconds, a bit like that horrible Grave yard red dot, that keeps on coming back. 5 CE for something which lasts for such a short period of time, and does almost nothing for you {except shock you from time to time, robbing you of vital health, lol is not very good. For people that solo a lot, NCP's can be a nice thing}.