I would agree here. Push to 1k and get the 4* covers, once your 4* is closer to being complete, then buy the covers. Generally the 5th cover in any colour is required for the character to be more useful.
If your luck is really bad, you could buy the rest of the covers for JG (5/0/5) and then pull a purple/green after you maxed it while you still need 3 blue covers.
If I was in your situation, I’d fully cover X-Force DP 5/3/5 given that you have X-Force Wolverine already fully covered. They partner well together and should allow you to consistently get the 1000 progression reward in PVP even if you don’t have any of the buffed characters at a decent level. However, this is with the assumption that you have the ISO to max level these 4*s. If you don’t, I’d wait to spend your HP until you can make effective use of whoever you’re leveling up.
It’s rarely worth it. A couple times I have bought 40 packs that I think might be considered worth it…
When Mystique was released I immediately realized the Winfinite combo with Magneto and bought 40-packs until I got all 3 of her covers, then maxed out her blue.
When XPool was released I bought a 40-pack and pulled 3/4 of the covers from his vauilt.
Having Mystique/Magneto pre-nerf really jump-started my 3* transition. I was destroying PvE events and DDQ before I really should have been. It was expensive, but I think that was money well spent. The XPool maybe not as much, I’m still not sure yet. I’ve got him (5/1/5) and XFW (5/5/3) both at 220 and use them together all the time, but they really aren’t paying off for me like Mystique did
I wouldn’t buy a 40-pack for the legendary token. That’s over 11k HP. You could spend that on shields in PvP and earn 10x as many 4* covers, and potentially legendary tokens as well depending on your roster strength.