We sometimes have a hard time finding the rent for the mosque and we want to add one euro to the price of a kilo of meat that is sold after slaughtering it in the halaal manner, with the aim of part of this euro going to the mosque and other parts to cover the expenses of transportation and so on for the person who is responsible for bringing the meat in his car; we give him a small amount of money in return for that. One of the brothers told the people who want to buy the meat about that and they accepted it. Is that Islamically acceptable?.
So long as those who are buying the meat know about that and have agreed to it, there is nothing wrong with it, because the Prophet (blessings and peace of Allah be upon him) said: “It is not permissible to take a man's wealth except what he gives willingly.” Narrated by Ahmad (20172), classed as saheeh by al-Albaani in Irwa’ al-Ghaleel (1459).
And Allah knows best.