I highly doubt El Shaw or Ox will be cheap. Hidden gems won't be found until a couple weeks after the actual game releases. The hidden gem criteria usually goes like...
1. at least 4 star skill
2. at least 80+ pac
3. pretty good shot (depends on power, etc)
and a couple others depending on position

Ehhh for hidden gems their some that say their less than 80, and feel like their 90+ :p .