I won't tell people how to spend their money. Hell, I just spent $900 on a new iPad a month ago and then another $100 to upgrade my mini 2 to a mini 4 in the past two days.
However, I will tell you the apple leather sleeve is JUNK for the money they are charging. I bought it, just to see it in person and I couldn't believe it. Very basic, very flimsy, doesn't seem to add much for protection. I like my $18 sleeve I bought on Amazon made by valkit.
P.S. just as an FYI I do buy the random Smart Cover and I have an apple case on my iPhone 7 plus, so I'm not just against their accessories. They are just highly overpriced.