It needs to be $8k-$10k, and it should've been changed a long time ago. There's no point in raising the range if they won't widen it.
I was saying 8k-9k as a temporary change if they keep playing this game this season, to give a higher psychological advantage to the player (citation needed) and not change the game too much this season. However, we do need increase the range soon, and 8k-10k seems like the best option, because of a wider and increased range.
With that said, I forget Check Game is still around at times given the show's preference for quick games, so when it does show up it would be nice if they could always set it up for a likely win and save the harder setups for the all quick games that get played more often.
Check game is one of the faster medium prize games, but I think that they still can alter the prize given, like a 4,999 mattress to make the game easier, or a $6,041 trip to make it harder. It would be nice if it was set up to be always won, but in reality, name four games set up to be always won. (I can only think of three. Clock Game if you use binary search, Now or Then if you know the technique, or Cliffhangers 20ish-30ish-40ish.)