How to express "Now, ..." in Chinese (the usage of "now" to draw attention to a particular statement)?
Now, you found out that the store B sells the same item in $8. But it is located in 8 miles away.

I am not a native English speaker, but I don't quite agree that now here means draw attention to a particular statement or point in a narrative. In my opinion, it means this sense in this context:

ADV You say &quot;Now&quot; to introduce something which contrasts with what you have just said. 然而
Now, if it was me, I'd want to do more than just change the locks.
然而，如果是我，我要做的远不只是换换锁。

I think there should be an implicit but in your English sentence. So, you could interpret that now as 可是现在, 然而现在，or just simply as 然而，可是.