I am currently waiting for my order to arrive (2015 TEP w/ KDSS), and had some thoughts like you did, except over KDSS instead of sunroof.
I was half torn on the KDSS, and it made the car a bit over budget. I did want the sunroof and softtex though.
End of story, I plan on keeping this car until I can give it to my kids. A few grand in the length of ownership is worth saving for. Especially if it's something you want. Maybe if you're gonna get rid of the car in a short while, not getting the sunroof is okay, but if it's something you really want, I believe it's worth it.
Having just got out of a WRX, I spent a lot of the time owning that car, wishing I had gotten an STi. Was the same story as above, and I won't make the same mistake again.