Vendor recipes bug ? help please

Hi there,
I discovered this very good game and i wanted to improve my game experience so i went to the wiki http://pathofexile.gamepedia.com/ the Vendor recipes section
I tried and i tried every time i want to sell 1 portal scroll to have 3 scrolls of wisdom i can't i went to see Nessa i proposed to her 1 portal scroll and in return she gives me 1 scroll of wisdom
i tried many recipes from the wiki none work for me :/
is it a bug ?
is it the wiki who is outdated ?
anyway thank you in advance for the help =)
Have a nice day
P.S : if you have a website like the last path wiki where i can see all the recipes that'll be good ^^

You read it backwards.

You can buy 1 Portal Scroll in exchange for 3 Scrolls of Wisdom, but you can only sell 1 Portal Scroll for 1 Scroll of Wisdom.

This is because the developers believe in your choices having some type of impact (the same reason that you have limited Passive Refund Points), even on something as low-level as scrolls.

In other words, it's a one way street:

3 Scrolls of Wisdom -> 1 Portal Scroll

1 Portal Scroll -> 1 Scroll of Wisdom

If your Scrolls of Wisdom are in short supply, I recommend selling 1 Orb of Transmutation -> 4 Scrolls of Wisdom. That is found on the wiki page you mentioned under the "Downgrade" section.

No i tried it both ways and it doesnt work here's a screenshot :
http://s11.postimg.org/htdtnraz7/Sans_titre.jpg

Please help me :/

Il faut que vous utilisez "Purchase Items." Dans la liste "Direct Purchases From Vendor" sont les recettes du "Purchase Items" bouton. Et il faut que vous parlez avec Nessa, Yeena, ou Clarissa si vous voulez Portal Scrolls. Elles sont dans Act 1, Act 2, et Act 3. Vous pouvez utiliser le "Sell Items" bouton pour toutes les AUTRES listes dans le wiki. Je vais editer le wiki (en) afin de ameliorer!

Excusez moi si vous ne pouvez pas comprendre mon francais. J'ai etudie dans l'ecole deux ans mais j'aime la langue francaise :)

le wiki francais: http://pathofexile-fr.gamepedia.com/Accueil

dans cet photo il y a le Portal Scroll "Purchase": http://i.imgur.com/Jl5F6Ri.jpg
Comment acheter? Ctrl + faire un clic

You have to use the "Purchase Items" button. The formulas listed in the "Direct Purchases from Vendor" list on the wiki are for using "Purchase Items" button. Additionally, you can only make the Portal Scroll purchase from Nessa, Yeena, or Clarissa in Acts 1, 2 and 3 respectively. When you use the "Sell Items" button, all of the OTHER recipes listed on the wiki apply. I will edit the wiki to make this easier to understand!

Sorry if my French is not easy to understand. I studied for 2 years in middle school and wanted to play around :)

French Path of Exile wiki: http://pathofexile-fr.gamepedia.com/Accueil

Here's a photo showing the Portal Scroll purchase: http://i.imgur.com/Jl5F6Ri.jpg
You can "buy" it by dragging it to your inventory, or by holding Ctrl and left clicking.

thank you i understand now ( ton français est bien ;) )
have fun ^^

Oh lord... i was blind too.. thanks for advice :D