My name is Maclean and I'm a Senior Support Engineer at eWAY.
Have the above fixes worked for you or do you require further assistance?
On the test gateway there is no requirement for the amount however the response code will be based off the last 2 digits of the total amount passed.
eg: Pass $10.02 you will receive response code 02 which implies a failed transaction. Passing $1.00 will result in response code 00 which is a successful transaction.
Please feel free to contact us on firstname.lastname@example.org