Is it proven that the Prophet (blessings and peace of Allah be upon him) used to bargain when buying and selling until he began to sweat?
Question

                I would like to ask how sound is what some people say, that the Messenger (blessings and peace of Allah be upon him) would haggle (bargain) over the price of goods until he began to sweat – or words to that effect.

Can this action really be attributed to the Messenger (blessings and peace of Allah be upon him)?
Praise be to Allah.
    Firstly: 

    The Prophet (blessings and peace of Allah be upon him) was 
    the best of people in attitude and the easiest to deal with, when he bought, 
    when he sold, and when he asked for payment. Worldly matters were not his 
    concern, blessings and peace of Allah be upon him, and neither were issues 
    of buying and selling his main concern. But he used to walk in the 
    marketplaces, and he used to buy and sell, teaching people in word and deed 
    the etiquette of transactions and the characteristics that the trader should 
    have of honesty, self-restraint, trustworthiness, good treatment of people 
    and loving good for people. 

    Secondly: 

    The Prophet (blessings and peace of Allah be upon him) would 
    bargain when buying – and bargaining means offering a lower price – not 
    because he loved to compete for worldly gain, but he was the teacher from 
    whom people learned the teachings of their religion with regard to business 
    dealings and all other matters, so he used to explain to them that which 
    concerned them in all their affairs, in both word and deed. 

    Moreover, being careful about how one spends money and trying 
    to save money in permissible ways is something to which people have a 
    natural inclination, and there is nothing in that that is contrary to good 
    manners or religious teachings. 

    Reflect on the attitude of the Prophet (blessings and peace 
    of Allah be upon him) and that which has been narrated from him in a saheeh 
    report: 

    Al-Bukhaari (1991) and Muslim (715) narrated from Jaabir ibn 
    ‘Abdullah (may Allah be pleased with him) that he was riding on a camel of 
    his that had become exhausted to the point that he wanted to let it go. He 
    said: The Prophet (blessings and peace of Allah be upon him) caught up with 
    me and offered supplication for me, and he hit it and the camel started 
    moving (energetically) as I had never seen it move before. He said: “Sell it 
    to me for one uqiyah.” I said: No. He said: “Sell it to me.” So I sold it to 
    him for one uqiyah and stipulated that I be allowed to ride it home. When I 
    arrived I brought the camel to him, and he gave me its price, then I left. 
    He sent someone after me and said: “Did you think that I bargained with you 
    in order to take away your camel? Take your camel and its price; they are 
    both yours.”. 

    It says in Subul as-Salaam: 

    This indicates that there is nothing wrong with asking a man 
    to sell you something that he has, or with bargaining. End quote.

     It was narrated that Suwayd ibn Qays said: Makhramah al-‘Abdi 
    and I brought some garments from Hajar to Makkah. The Messenger of Allah 
    (blessings and peace of Allah be upon him) came to us on foot and bargained 
    with us for some trousers, and we sold them to him 

    Narrated by at-Tirmidhi (1305) – he said: it is hasan saheeh. 
    Also narrated by Abu Dawood (3336), an-Nasaa’i (4592) and Ibn Maajah 
    (2220). 

    Bargaining refers to haggling between the seller and the 
    buyer when deciding the price, as it says in an-Nihaayah (2/425) 

    This bargaining, in a moderate and reasonable manner, is a 
    sign of maturity, sound mind and knowledge of the market price. This is 
    something praiseworthy because such a person is less likely to be given an 
    unfair deal or be deceived or cheated when buying and selling. 

    Hence the fuqaha’ said: you may know that the son of a trader 
    has reached maturity once he knows how to buy and sell and bargain. 

    See: al-Mawsoo‘ah al-Fiqhiyyah (22/215) 

    With regard to what is mentioned in the question about the 
    Prophet (blessings and peace of Allah be upon him) bargaining until he began 
    to sweat, and the like, we know no basis for this in any report from the 
    Prophet (blessings and peace of Allah be upon him), and it does not fit his 
    character and easy-going nature in buying and selling, or his kindness in 
    all his affairs. 

    And Allah knows best.