I picked up a 16GB mini 3 with cellular at Best Buy during their $175 off flash sale. This would be used by my wife (replacing a broken 16GB mini 2), whose use is pretty much limited to internet browsing and email. I am wondering if I should return it and just get her the mini 4 for longevity purposes or if the discount is sufficient to justify buying the older tech. She isn't one to replace her devices very often. As an example, she is still happily using my old iPad 2 when in the house. Thoughts?