So I ran several missions since servers opened up today (11 to be exact) I have a slicing high enough that these 11 got it to 400 on the last one and I've netted the following results.
Credits Spent: 18,110
Credits Received: 23,149
Net Profit: $5,039
+1 340 Diplomacy Mission
+1 300 Bio analysis Mission
That was roughly 3.5 hours worth of slicing (there were times I could not get back to it right away).
I would say on average doing the same thing pre nerf I would have netted 15-20K.