I remember when I just started playing this game I would get an Epic card from the regular boxes at a rate of 1 per 10 or 20. During the event to fulfill one of the quests I had to drop around 800000-1000000 bucks. That's anywhere from 55-70 packs. 

Also I decided to drop some actual cash for the event and bought some gems. When I used to grind free gems I got 2 legendaries out of probably 5-6 packs.  I decided to use some extra gems  to get the gold packs and got 1 legendary from 9 packs. 

Am I just really unlucky? Is this similar to what anyone else is seeing? 

Seems like bad luck / bad RNG?

On the one hand, it only took me 4 or 5 tries to get the Epic (blue card) out of the silver (15000 cash) box for the event quest.  Probably very lucky on my part, I'm typically seeing 1 out of 20 or so like you.

On the other hand, I've only gotten one legendary (red) card out of the gold (50 gem) box the whole time I've been playing.  Which is probably bad luck on my part, but like you I've only been grinding free gems from daily logins so that's probably only 10-12 boxes total.

The rates on both silver and gold chests were definitely worse for me this week than they ever have been. However, I didn't keep track well enough to provide any type of statistics. But this is the first week I've played in probably a month or so, so I don't know when they changed (if they really did).

We have the same experience, spend over 1 million to get the one Epic card from a Silver Box, never had that poor a run before. (Was lucky it was the Proctologist though, still needed that one!) However, we never had a Legendary from the Gold boxes (also just from free gems), so it seems really RNG.

I feel the epic rate from silver box have gotten worse. I saved up for 40 pulls and got 1 i epic item and 0 epic character. I only passed that epic character quest from the daily bonus Journalist reward. Guess I'm lucky that happened to be the day so I wasn't stuck on the quest for too long. 

So bad luck for the Silver boxes, but excellent timing on the Journalist haha! Nice! We saw we were 18 days off from the Journalist so that was not going to work, did have to grind out the cash for Silver boxes until finally one gave up a Procto.  :):)