the i7 7700k is totally worth it for your purpose.
in terms of realtime performance nothing beats this cpu today, its a beast!
depending on what you do, the i7 can be up to 50% faster and even more because the i5 lacks Hyper-threading,
then there is bigger cache, higher base clock, higher single turbo, higher all core turbo....
and resell value
i have to add the i5 7600k isn't a bad cpu at all, it will get your work done as-well.