Today I realized the same problem in 4 different game parts. And the question to you is how we should generally or in detail deal with it, as GM?
There are values or ratings that are the base for the costs, but they can easily change over time.
1. Connection ratings, you buy a Connection with 2 ratings that define your BP or Karma costs at the start of the Game, but later in the Game that ratings could raise. Does the player have to pay the new rating with his Karma?
2. Spirit Pact at character generation the spirits Edge define the BP or Karma costs for the pact, but later in Game it can raise its Edge Attribute. What's about the Quality cost does it raise, too? And has the PC pay the new price? And if is it only the difference between the two prices or has he pay the whole new price?
3. Resonance Bond (see 2., it's the same question and problem, because it's the same game mechanic)
4. Fresh from the "War!", Feral Resonance, in this case the TM has to pay Karma equal to the feral AI’s rating. But the rules from RW (see p. 197), say that a feral AI improves its rating over time as growing effect automatically. So what does it mean for the PC, does the character have to pay every time the AI's rating is improving? Or is it a one time bound cost?
Greetings
UV