Fee to add bag after booking

I cant access site, so can you advise the cost of adding a bag after booking please, flight to Spain in March
Many thanks

Copy from Ryanair website:
Checked Baggage - Fees per bag per one way flight
(Each passenger permitted to check in up to 2 bags)
Purchased on Ryanair.com Purchased at Airport or Call Centre from 5th January 2014
(Euro € / UK £) €/£ €/£
1st/2nd Bag (15kg) - Low Season* from***
€15 / £15
€30 / £30
1st/2nd Bag (15kg) - Low Season* - Selected Flights** from***
€20 / £20
€40 / £40
1st/2nd Bag (15kg) - High Season* from*** €25 / £25 €50 / £50
1st/2nd Bag (15kg) - High Season* - Selected Flights** from*** €35 / £35 €70 / £70
1st Bag (20kg) - Low Season* from*** €25 / £25 €40 / £40
1st Bag (20kg) - Low Season* - Selected Flights** from*** €30 / £30 €45 / £45

High season starts 28/03. Maybe you have to add the fee for creditcard payment.