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better go with 16 GB the price increment not match with the cost increment.

Let see how you could save. big files:
1. Music - itunes match. the cost to top up to 32 GB is more than your subscription
2. Photos - set auto backup to dropbox/skydrive, etc
3. Videos - delete when not use
4. Apps - delete when not used.

for iPad though, I prefer 32 GB as the newsstand magazines are huge! some can be around 500 mb/edition.
 
I think the sensible answer is buy what you can afford right now. I am in a similar boat. I don't mind managing my phone better, taking photos off now and then, wiping text conversations, and downloading apps when I need them rather than putting them all on at once.

I have had 16GB for the past few iterations of the iPhone and have come close to filling it up. You could always get the 16GB 5S this year and if your needs change come next year and you are struggling to manage your 16GB, get the 32GB iPhone 6 :)
 
I've always believed bigger is better, but that's mainly because I download a lot of music. It doesn't seem like you need the 32GB right now. Do you plan on upgrading to a new iPhone in 2 years? You could always switch to 32 then.
 
This is a good point. VZW gave me $200 store credit for my 16gb 4S, while the 32GB only received $210 and 64GB $220. I wouldn't base the entire decision upon it though. Just keep it in mind.

Yeah it definitely appears that the higher capacity HD does not carry much of a premium on the resale markets. Although companies like BuyBackWorld and Nextworth do offer slightly higher prices for Apple products with bigger drives, you'll never recoup the extra $100 - $200 you laid out. That stays in Apple's pockets.
 
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