Not that I'm aware of. I'll certainly double-check when the time comes, as I agree that is a good deal (especially since I think Apple Care is included). We purchased our VW Jetta TDI that way too, and if it weren't for VW cheating and the scandal and such, that worked out pretty well. I'll always take a zero-interest loan if I'm sure I can pay it (which, if you have the money upfront anyway, you can.)
Oh for sure, each person has various use-case and needs. I'll want a bit more storage too, as I'm sure I'll use the camera a lot more (the one on my iPod touch is useless), especially until I get a dedicated DSLR setup for shooting video for business... and even then, as a photographer I know says... the best camera is the one you have with you.

You miss a LOT of stuff if you only rely on a DSLR.
But, my main caution about RAM, as I've mentioned over and over, is my concern about iOS's update track record. You might find that iOS 10 makes your 1GB phone too sluggish to use effectively (the way iOS 8 made all the 512k devices). In fact, once Apple gets a sizable percentage on 2GB, I can almost guarantee it. If I didn't fear that, I'd just have purchased a 5s some time ago.
And, again, the problem with 16GB isn't that it won't do for some... it's about Apple's perception in the market place as a premium product with too much of a limitation for the price (and in some cases, a limitation that ticks people off). I could care less if they start the line-up at 8GB or 16GB, etc. as I'll be getting the 64GB. But, my concern is for Apple's future.