For how long will the skins that are going to be released be available for purchase?

I have seen this post

http://na.leagueoflegends.com/node/7557

and this one

http://na.leagueoflegends.com/node/7431

I was wondering how long they will be available for purchase after their release/re-release. I just moved to another state and am job searching. I would like to be able to buy these skins when I do find a job which could be a few months from now and even after landing a job it could be a few months after that until I can afford to buy a few skins. Thanks for your time and have a great day.

I saw that it says temporarily but that is vague.