What price would you consider fair for the upcoming kits?

It does depend, but if it is really half an SP, then half the SP price is fair. However, I have been starting to expect varied prices. If they were going to follow the old pack formula of set amount/scope for set price, I do not think they would have taken all the effort to distinguish kits from other packs. I think if it was simply going to be another pack type, it would get a shelf on the start menu pack page and they would call it a day.