Create an instance of proxy class for every ListItem

I created a client application by consuming API's,  loop through a small set of List  & call the API . I get the following error"The maximum message size quota for incoming messages (65536) has been exceeded. To increase the quota, use the MaxReceivedMessageSize property on the appropriate binding element"

even for a small set of List items(i guess this may be due to huge XML  string i get as a response). Instead of changing the config file to increase maxReceivedMessagesize similar to below mentioned i was thinking of creating an instance of proxy class everytime i loop through the List. How much overhead is creating a instance of proxy class??

<basicHttpBinding><binding name="APIWebServiceSoap" allowCookies="true"
                 maxReceivedMessageSize="2147483647"
                 maxBufferSize="2147483647"
                 maxBufferPoolSize="2147483647"><readerQuotas maxDepth="32"
               maxArrayLength="2147483647"
               maxStringContentLength="2147483647"/></binding></basicHttpBinding>