Apple has silently pulled the ipad mini from the store here in Ireland as well as everywhere else by the looks of things and this of course does make some sense due to its age and as per norm with most tech items they do have a shelf live in retail,but you can be sure to find them with resellers on the net or in retail here as most electrical stores do sell them,there may be some inventory left and it could be either pulled or sold off cheap but i would be weary with the warranty..
The tablet has been on the market since 2012 so its had a good run to be fair and it was time to move along and discontinue the model,Apple do the same with their iPhones so its nothing to worry about its just the life cycle of the product.