Kedushas Beis Keneses

The gemarah in Megilla (Daf 26-27) discusses the laws behind selling a shul. The question addressed in the Rishonim is what kind of kedusha does a shul actually have. The Ramban (brought in the Ran) holds that a shul doesn't have any intrinsic kedusha. It is considered tashmishei kedusha like a lulav and sukkah. Once people decide that they no longer want to use the shul, it loses it's status of tashmishei kedusha. The Ran on the other hand understands that a shul does have kedusha which can't be taken away without some type of pidyon.

There are several nafka mina between the 2 shittos.

1) The status of the money: Everyone agrees that the money you received has some sort of kedusha the only question is why. The Ramban understands that everything revolves around the da'as of the community. Once they decide they don't want to daven in a shul the shul loses any kedusha it has. However, this da'as does not extend fully to the money. Their da'as is that a lesser kedusha extends to the money. The Ran on the other hand holds that since the money is in effect a pidyon for the shul, there is kedusha on teh money. However, it is a "kedusha kilisha", a lesser kedusha since this money was never designated as a davar sh'b'kedusha.

Interestingly, both the MG"A and Taz in O.C. 153 hold that the money has no intrinsic kedusha.

2) The gemara says that if you sell a shul with "7 tuvei ha'ir b'ma'mad anshei ha'ir" then you can use the money for whatever you want. Once again the question is why. The Ramban understands that since you have "7 tuvei ha'ir b'ma'mad anshei ha'ir", this means that teh community does not want any form of kedusha to remain at all, even on the money. Since no kedusha remains you can use the money for whatever you want. The Ran understands the reason to be that it is a special halacha that with "7 tuvei ha'ir b'ma'mad anshei ha'ir" you can remove the kedusha from teh money without having to transfer it anywhere (kedusha paka b'k'di).

3) Giving a shul as a matana. The gemara brings a machlokes whether a shul can be given as a matana. The tzad that itis muttar is because you are getting some ha'na'ah by giving it away. The Ran understands this k'peshuto. Since you need to redeem the kedusha of a shul, in this case you are redeeming it with the hana'ah. Furthermore, we are dealing with a case where it was given with the consent of "7 tuvei ha'ir b'ma'mad anshei ha'ir". You need this p'rat because the hana'ah is going to chullin and is not remaining kodesh. The Ramban understands that you are actually getting some d'var mitzvah back and that is what causes the community to give it away. Also, you don't need "7 tuvei ha'ir b'ma'mad anshei ha'ir" since you only need "7 tuvei ha'ir b'ma'mad anshei ha'ir" to remove the kedusha from the money which doesn't apply here.