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.
(..) It was just a bit of fun. Oh,you're probably right,as usual. -You wiII keep an eye on Frodo,won't you? -Two eyes. As often as I can spare them. -I'm leaving everything to him. -What about this ring of yours? -Is that staying too? -Yes,yes. It's in an envelope over there on the mantelpiece. (..)2001 The Lord of the Rings: The Fellowship of the Ring