I do egg missions every day, still 3k sigils to be saved are better for me. Here is my math
I have elite and 100%. That gives me 116 / 232 / 464 tokens for 1h / 4h / 20h missions. 125% will give me 132 / 261 / 522 tokens. Each day I do the 20h mission, let’s say, 3 4h missions (morning, evening and one somewhere during the day) and 5-8 1h mission. Let’s take 8, so 125% will look better. So, each day I have 464 + 3 * 232 + 8 * 116 = 2088 tokens. With 125% it will be 522 + 3 * 261+ 8 * 132 = 2361 tokens. The season lasts 365 / 4 = 91 day. Bonus is not from the beginning, but again, let’s count like it is.
With 100% I will get 91 * 2088 = 190 008 tokens. With 125% it will be 214 851, which is 24843 tokens extra. Now, what is better - 3.15k sigils or 24843 tokens? Let’s compare them using rubies. If you farm tokens, with 100% bonus and elite account you get 80 tokens for 30 rubies (level of zeppelin doesn’t matter, as the cost in rubies scales with amount of tokens). Ok, let’s take 90 tokens (which 125% bonus give us). So, to farm 24843 tokens I will need 24843 / 90 * 30 = 8280 rubies (or 9316, for 100% bonus). How many rubies I will need to get the 3.15k sigils that I’ve spent on this bonus? From 10 supersigil chests we get about 1250 sigils or so for each 5k rubies in average, if we take into account the bonus chest after each 30 opened chests. 3150 / 1250 * 5k = 12.6k rubies.
So, to summarize for those, who are not sleeping yet and haven’t scrolled down in fear of numbers… For 125% bonus, I will spent 3.15k sigils extra, and will receive 24.8k tokens. Same amount of tokens I could get by farming, if I spent 9.3k rubies. Same amount of sigils I could get by supersigils, if I spent 12.6k rubies. Since I always open supersigils at the end of season, I would better take 3.15k sigils.
There is additional bonus of 125% bonus - prizes from two lines of eggtoken bonus, which I’m not including (could be also converted to rubies for comparison). I don’t think it will add much, and at the same time, in calculations I’ve used like I have 125% for the whole season. Due to that, 100% is better for me than sigils. If you farm during season - 125% will be better, since you get those extra again and again, and at some point it overweights the 100% - because of the difference 80 vs 90 tokes for 30 rubies. But I don’t farm - so 100%.