I don't mind spending $1100 to $1300 - as long the lens can deliver high IQ.
Unfortunately, the FE 24-70 f/4 is not worth spending that much
... I think you'd be better served with the FE 35mm f/2.8
As I said earlier, it is better than the 28-70 kits lens, but not so much that one would want to spend $1047 (in USA, it costs $1198).
Sometime in the near future I
may get the Canon EF 24 f/2.8 IS, EF 35 f/2 IS and use them with the metabones adapter ... that way I get lenses that can be used on both the systems and still get Image Stabilization ... also I've seen some images of people using those lenses on the a7 and am pretty much convinced.