I really don't understand people who wait for anything other than an iPhone. Everyone knows when the new iPhone is being released. Everything else, you could be waiting for a year or more for the new one. You could wait until October and then they could announce it in November. Or it could be March...Or next October...
If it fits your need for the price, buy it. Maybe if there is a very reliable rumor, but there is nothing like that on the Mini.
I wait if the latest model isn’t a big enough upgrade over what I already have given the asking price.