The Runner approaches a piece of ICE during a run. The Corp rezzes Tollbooth.
The Runner has 3 credits. Can he use Net Shield or New Angeles City Hall to spend a part of his money so that he doesn't lose it all? What about using the Corroder?
You cannot use prevent or avoid effects unless the condition that they are preventing/avoiding is occurring. You could use a non-prevent/avoid paid ability such as on Corroder to spend 1 credit when the Corp rezzes Tollbooth. We will take another look at this scenario before releasing the next FAQ, but that is currently a valid interaction.