Here's the rest of my current Atelier files, all picked up at the Internet. If I remember correctly, the OST's to Two and Three came from GoronMoron's files, and the Arrange Tracks collection, from Galbadia Hotel itself. Enjoy and let me know how the links behave.

http://download655.mediafire.com/c6sw492154wg/ug35d8y4upn7buw/Atelier+Iris+2+The+Azoth+of+Destiny+OST+%28Disc+1% 29.zip

http://download1306.mediafire.com/g62ws6sct6mg/46l68oniyze4rva/Atelier+Iris+2+The+Azoth+of+Destiny+OST+%28Disc+2% 29.zip

http://download284.mediafire.com/2ks98kkox6fg/njh452jffbng4f1/Atelier+Iris+Eternal+Mana+2+Arrange+Tracks.zip

http://download645.mediafire.com/b5h9cthrriqg/5sdmd1y07sez5u4/Atelier+Iris+3+Grand+Phantasm+OST+%28Disc+1%29.zip

http://download1162.mediafire.com/82kn1d8ny8kg/vuwm6dirbf152j1/Atelier+Iris+3+Grand+Phantasm+OST+%28Disc+2%29.zip