The cost of Summon History is X blood. When do I declare the cost I
am going to pay for the card? When I locate the piece of equipment,
retainer or ally (or crypt card) I want or when I declare the action?
For example, Magic of the Smith lets you search through your library
for a piece of equipment. If you have different pieces of equipment,
you can decide on which one you want after the action is successful,
then pay the cost as normal.
Summon History
"[tem] Search your library and/or ash heap for an ally, retainer or
equipment whose cost is X or less. Put that card in play (on this
vampire and with starting life from the bank as needed).
[TEM] Search your crypt and/or ash heap for a non-scarce vampire with
capacity X or less. Put that vampire in play, with no blood."
