I could have sworn the odds used to be better if you bought 10 or 40 packs, but looking at them now… doesn’t seem to be. 3*s go from .6% each to .7%, that’s about it.
It really comes down to the guaranteed LT, and the instant rewards mentality. How many HP would you pay for that chance at a 5* cover and/or a 4* guarantee?
If you’re just looking at the math, the odds of not pulling a 4* cover in a 40-pack are very small - 14% (this includes you pulling IW and Star-Lord though, and I’ve still managed to do not pull any 4s in four 10-packs). However, if you’re specifically looking for a top-10 4 you have a 45% chance of not pulling one. Top 5? 67% chance. Assuming 112 pulls though (the price of a discounted 40-pack in terms of HP expenditures at 100 for a single token), and your odds of a top-10 are now 89.5% and a top-5 are 67.6%.
Given that 5s are a 10% shot, and each 4 is a 3.8% shot… that’s a 29% shot of a top-5 4* and a 48% shot of a top-10 or 5* in one LT. When you combine that with the other 40 tokens from the heroic you get:
5*: 10%
top-5 4*: 45.73%
top-10 4*: 65.9%
If you want a specific 4* (ex: Ice Man, not Ice Man Blue):
40-pack: 7.7% of pulling it not counting the LT. 11.21% including the LT.
112 tokens: 20.1% of pulling it.
Ergo, if you are spending 11,200HP on heroic tokens, unless you want that 10% shot at a 5* you are going to want to buy individual tokens, assuming you can tolerate waiting 112 days.
These are all pretty low odds in general, so take that for what it’s worth. Also, because I got curious:
Number of heroic tokens required to pull a specific 4* with >90% accuracy: 1151
Number of Legendary tokens required to pull a specific 4* with >90% accuracy: 60
Number of Legendary tokens required to pull a specific 5* with >90% accuracy: 69
Number of Legendary tokens required to pull a specific cover of a specific 5* with a >90% accuracy (assumes even distribution of covers): 209