How many transactions can a bank/person make per block I’m trying to determine if bitcoin is too expensive for a bank to use. 

Assume that a bank would use bitcoin for something like confirming transactions between itself and another bank I’m asking how many transactions on a single block can a bank make?

I’d like to answer the question 1 Bitcoin Cost / Number of transactions = cost to bank / transaction

Any thoughtsb   Is this the correct way to think of the worth of bitcoin?
The cost of a Bitcoin transaction doesn't scale respective to the amount that is being sent, but according to the amount of data that the transaction occupies on the blockchain. The Bitcoin blockchain produces about one block every 10 minutes which can (depending on the transaction composition) carry about 2,000 – 4,000 transactions.