With the exception of one or two cards such as firefly queen, all cards are pretty cheap.
The entropy mark is for faster quanta for all elements from supernovas, that, by themselves, give almost all the quanta needed to about half, for all cards except those one or two expensive cards.
In this deck's idea note that with one single supernova you have half or over half quantum needed for all cards except:
-fire storm
-firefly queen
-bone wall
-eternity
-miracle
-phase shield
(if im not wrong about the card's cost as im not sure i know them by heart)
And note that out of those, fire storm, bone wall, phase shield and eternity (All but firefly queen and miracle) you still get almost 50% of quantum needed.
2/5 quantum for all of them if im not mistaken. almost half.
I sometimes lack quantum when i get too few towers yes (altho i just have 7-8 towers) but it seems to work pretty well.
You just need 2 supernovas, 1 supernova and luck with 1 tower, or 1 supernova and 2-4 lands to play all your hand (then again, except the most expensive).