Spending HP on 4* Covers: best vs worst covered

I have 7 free roster slots and 5525 HP. Since buying covers for HP is going away soon, I was going to purchase 2 covers for my 4* characters. Trouble is, my most covered characters are also some of the worst 4*s!

  • 1/3/5 Elektra
  • 3/1/3 Ant-Man
  • 1/4/2 Invisible Woman
  • 2/1/4 Sam Wilson
  • 2/2/3 Thor
  • 2/2/3 Wolverine
  • 3/1/2 The Hulk

It goes down from there. Would I be better off spending the HP on top-tier characters where I have very few covers? Or invest in characters that are already decently covered?

So I’ve gotten a large cluster of LTS yielding Red Hulk green and purple, and mine is now 1/5/4. I’m rolling around the idea of buying the last purple cover tomorrow before the cut over to CP for cover upgrades.

What say you? I already love the amount of damage he does with 18 green AP, and have found it difficult to reach that much AP in a reasonable number of rounds. The jump from 4 to 5 purple covers seems pretty huge.