I didn't buy Shantotto Ascension, A Moogle Kupo d'Etat and A Crystalline Prophecy back in the day.
I want to add them to my account but doing so would cost me £8 each, can these prices be lowered or is there another way to get them added to my account that won't cost me £24?
Usually during free login campaigns they offer the Ultimate Seekers version of the game for 9.99 usd, no idea what that converts too but it includes all mini expansions. Maybe pick it up next sale.
Can you apply those codes to an old account? It's so annoying how difficult they make it, they could just lower the fee for these expansions when bought through playonline.
Should be able to, yes, even if bought via Steam for example (at least I've done it successfully before).