I don't think anyone has mentioned about this before. I recently came upon this lv 5 Peter Lee's Sword in Esmeralda's shop, which wass quite shocking for me since I had never seen a unique item in shops for this kind of games.
Sorry for my bad shooting; screen-capturing somehow doesn't work.
[img:left]
http://tinypic.com/view.php?pic=2lafzvn&s=8[/img]
I am pretty sure that it is a random refresh because I actually can reshufflle shops twice per level because there is a around 3000 XP gap between Jahan/Madora and my hunters. My first refresh using Jahan didn't see this sword but only after my hunters got to level 5 some time later this sword showed up.