Thats is what I call "Rafael condition" for lenses - better than new or mint
By the way I had the opportunity to hold an used 15/3.5 ais at my hands in a shop at Padova, Italia - EUR 600 paying in cash; but did not bought it because:
1) not a Rafael condition lens - perhaps a 9 in BHphotovideo ratings;
2) no original front cap & rear filters ;
3) it is not the 15/5.6 QDC - the last one I need for my collection
;