We are unable to put an exact figure on your new repayments because it depends on both tickets' relative values and the amount outstanding on your loan. However we can offer some rough guidance!
The general rule is: if you're moving from a cheaper ticket to a more expensive ticket, your new repayments will always be more than the cost of the equivalent monthly ticket. You can think of it this way: every month you pay towards your "free" 12th month, which is now for a more expensive ticket.
As such, we adjust your repayment to take into account the lower contributions from your original ticket.
The reverse is also true: if you moved onto a cheaper ticket, your repayments will be less than the equivalent monthly.
We take into considerations all payments to-date, alongside the cost of the new ticket, and then create you a new repayment plan on that basis - so you'll never be out of pocket.