iPhone 5s (or 6) versus iPad Mini with Retina Display?

[Strong]

I guess you are more knowledgeable than me about Apple products so here it goes:

I have a contract that is ending pretty soon so I will have to get a new phone. However I'm not too sure about getting an iPhone because I use data a LOT hence more expensive monthly payments. Furthermore, the screen is too small for my interest and I use apps quite a lot.

On the other hand, I absolutely loved an iPad Mini with Retina Display. The screen display is a huge bonus, and because of the storage capacity, I can download as many apps as I like. However my biggest concern is that what if the latest product comes out and I've just wasted my money (hypothetically I buy the current iPad Mini)?

I really want to get an iPad Mini but I can't upgrade it as easily as iPhone because my carrier allows us to upgrade the version to the newer one. So...what's yur suggestion? If I choose an iPad mini, I can get a cheaper phone which I don't mind either. It's just that Apple always releases new products and I can't keep up buying the newer version every time it comes out.

Any tips? Thanks~

P.S. I'm in nursing school so it's ideal for me to read the PDFs versions of textbooks while I commute.

 

[Strong]

BTW, I don't want a Nexus...I love Apple products but I can't afford both an iPhone and an iPad mini.

 

[authentic]

I think you would like iPad Mini Wi-Fi + Cellular ($14.99/monthly under AT&T)

iPad mini with Retina display Wi-Fi + Cellular for AT&T 16GB - Space Gray - Apple Store (U.S.)

 

[Chevy57]

My cousin have AT&T iPad mini. She love it, too. 14.99/mo at 250 mb and mostly use wifi.. $30/mo at 3 GB that is cheaper price than other carriers. Can add any VRS app.