To what extent is a Runner forced to take actions to pay for a Tollbooth?

Question

Playing against a Shaper (Kit) deck, I had a situation where the Runner encountered my Tollbooth with zero credit in their pool. They did have 2 credits on a Ghost Runner and also had a Cloak (with its recuring credit unused this turn), a Refractor and a Net Mercur (with no credits on it) installed:

My question is, when this Runner encounters Tollbooth in this situation, to what extent are they forced to take actions which make credits available in order to pay the 3 credits required by the Tollbooth?

Must the Runner spend credits from a Ghost Runner if they are available? I believe the answer to this is yes, but some confirmation with reference to the appropriate rule(s) would be helpful.

More interestingly, is the Runner in this situation obliged to use their Cloak to take some action (i.e. using the Cloak credit to invoke one of the abilities on the Refractor, say the +3 strength) which will result in the Net Mercur gaining a credit, which in turn can be used to pay for the Tollbooth's encounter action?

Or does the Tollbooth only force the Runner to spend credits which are directly available without any other actions taking place first (and must they only come from the credit pool)?

Answer 1

From the official FAQ, regarding Tollbooth:

The Runner must pay 3 [credits] if he or she is able to do so, even by spending temporary credits (such as bad publicity credits).

Also from the FAQ, on encountering ice:

When the Runner encounters a piece of ice, he or she must resolve any abilities triggered by the encounter before he or she can trigger paid abilities or break subroutines.

If there are at least 3 credits on Ghost Runner and/or Net Mercur when Tollbooth is encountered, then they must be spent upon encounter. If the Runner doesn't have 3 credits available to spend at that moment, without triggering other abilities such as Cloak's, then the run ends.

Answer 2

In your specific situation, the runner must end the run. Even though spending credits from Ghost Runner would create a credit on Net Mercur, all three credits must be paid at once, and paying part of the cost is what would create the credit to pay the rest. The credit on Cloak cannot be used for anything other than ice breaker abilities, so it cannot be used to pay this cost.

Any other abilities that would create the credits (ie Tech Trader) cannot be used, since the last paid ability window before the toll must be paid is past by the time the runner encounters the ice.