What are you doing.
Stop giving me these expensive trades.
Kala Stahp.

inb4 i run out of resources by 2019 with these Kala deals

I measured optimal gem usage for getting enough gems for 2 of these (WITH perfect luck) is a 4% chance of 125 (5 level 1 springs) X 4 (to get 8 level 2 springs) x 2 (you can only get a max of 1 Secret lifespring at 20%)
Result: 2 level 4 springs, 1000 gems to get that far, and only a 4% chance of that happening. on average, it would take around 5-6 thousand gems to get 2 Secret Lifesprings. and i just got 2 for a minor setback.