actually tony it can cost them a lot to send in pounds sterling and if sending from the euro zone if they select send in euro's and shared charges there can be no bank charges except a small fee from your bank to change it to pounds.
otherwise it can cost typically 20 pounds to send, you could ask your bank what it would cost you to receive in euro's and change to pounds, you may find that your customers are much happier paying a little extra for your costs than paying a lot more in fees their end.
if and when you get a chance it may pay you to ask about this.