It's a really hard decision. I don't see the point in owning both a 35 and 50mm. But it feels redundant to have a 16-35 and a 35 prime. But then again, I guess they are completely different lenses for different purposes.
OMG....I did not see this when I wrote my intial reply to you. But NO,no,no,no! STOP buying and selling s**t! It's not "redundant" to have a 16-35mm zoom and a 35mm prime. NOR is it redundant to have a 35mm and a 50mm--they are three, very different tools.
D_i_f_f_e_r_e_n_t. Not redundant. WIldly, wildly,wildly,wildly different. 35mm is not at all like 50mm. There's 35mm, 40mm,43mm,45mm,50mm,55mm,58mm,and 60mm. Just stop selling stuff, and learn to use more than one thing. Keep some stuff around for a few years. Or a couple decades.
Ever wondered why all these different lengths have been made into primes, by one camera maker or another?
(Oddly...EXIF combing from my crop-frame days showed the 35-70mm AF Nikkor
used at 43mm on MANY of my favorites pictures...)