He got there 'with (only) minutes/seconds to spare'. [=he got there only minutes/seconds before he needed to; he got there just in time]
When they go on vacation, they 'spare no expense'. [=they do not worry about spending too much money; they spend a lot of money]
He said that he would 'spare no expense' [=he would spend as much money as necessary] to make the restaurant successful.
(..) l'm sorry ! l'm sorry ! l'm so sorry ! - Lovejoy put it in my pocket. - l know ! l know, l know, l know ! Rose, you have to find a spare key, all right ? Look in that cabinet. lt's a little silver one, Rose. Silver... These are all brass ! Check right here, Rose. (..)1997 Titanic