If I'm recalling correctly, in Japan where Tengas are made, items of this sort are required to have a recommended maximum number of uses. I can't remember where I read that, so I could be wrong. But if you take care of them and keep them clean, they can last a lot longer (though it might also depend on how rough you are when using them).
And even if you were to throw it away after 50 uses, you still paid about $1.50 per orgasm - less than one-time use sleeves. And that's if you get it at full price.
... Somehow I just made the Flip Hole sound like a really cheap prostitute.