Fulfilling a social obligation when the price is too high

I settle for the following question, which is relevant to many different situations:
If society imposes an obligation on a person for a service that is not worth the cost of the obligation, is he morally obligated to fulfill it?
For example: A person prays in a synagogue that charges high membership fees. For him, the use of the synagogue is not worth the price asked, and if he is forced to pay, he would prefer to pray in another synagogue that is further away. Is there a moral problem with evading payment as long as he continues to pray in the synagogue, or should he leave?
Another example: A person lives in a country where military service is mandatory. Living in the country is not worth the cost of military service to him, and if he is forced to enlist, he would prefer to move to another country. Is there a moral problem with continuing to live in the country and avoiding military service, or should he move to another place?
On the one hand, it can be argued that it is immoral to receive a benefit from society without returning anything, and therefore such a situation is out of the question. On the other hand, it may not be logical to require a person to pay a higher price than the consideration he receives, and therefore, as long as his evasion of his duty does not harm the public (because it is only one person), there is no problem with this.
 
What do you think?