The lowest cost way for the Club to collect the annual subscription is by Direct Debit from the members account. This costs MSCC NOTHING and the money is immediately in the bank.
The £1.50 was set as a way of "incentivising" people to change to a DD. Using a card, debit or credit, has an additional admin time for our Membership Secretary. The actual cost to the Merchant Service provider is less.
When we ran our Company, which was about the same turnover as MSCC, we paid 1.2% on Master Card and Visa, Debit cards were 30p. That was a rate through the Federation of Small Businesses, far, fat lower than we could have negotiated with a bank or card merchant.
Some have asked why don't we take payment through PayPal. Compared with most card services Pay Pall is simply unacceptable, 3.4% +20p. So on £40.00 it would be £1.56.