calculate transaction fee in a block I want to know how one can query bitcoin core via json rpc or other methods to find all the transaction fees in a block? API queries are not useful as they have a rate limit.

Here is an example block, for which i want to calculate transaction fees 

block number 395545
As the block id is known, the fee can be found from the coinbase itself without an overhead. Maintain a simple map for reward points saying blocks between 0-149 gives 50 BTC, next 149 25 etc.

Now, the first transaction in any block is always a coinbase tran. 
Coinbasetran->vout[0] - reward = Fee (actual fee + unclaimed change)