Easyjet: Book bike as luggage now vs later?

I have a friend’s wedding abroad next summer, hope to be taking my bike to get out and play in the surrounding days but not totally sure yet (if there aren’t others up for some real riding then I’d just hire for a day or two). I want to buy my Easyjet flights pretty soon while they’re cheap and I have cash on hand, so does anyone know if I’ll lose out on the best prices if I was to just book with handluggage at the moment then add my bike and/or hold luggage later, vs just booking with the bike now?

I’m sure it just costs the same to add it later as it does at the time of booking. £70 for the bike and £30 for hold luggage. Just go to “manage booking” when you want to add your bike/case.