In the illustrated example, an end user performs simulation using the end user terminal 1100 as in the foregoing first or second example. That is, the end user terminal 1100 transmits information regarding a function desired to be realized in the system 10 by the user and/or the already possessed element 100p to the server 1300a (S061) and the server 1300a transmits simulation information to the end user terminal 1100 (S062). When the function supplied by a combination of the proposed elements 100 satisfies a request, the user referring to the simulation information can purchase the element 100q that he or she does not yet possess. At this time, payment of a price from the end user to the service provider is performed through, for example, a settlement process between the end user terminal 1100 and the server 1300a (S063).