Item for Sale -- disappeared from Shop

[jfp3]

A little background: Bought this great game a few days ago and have been running all over the starting Island bringing up my level slowly but surely. I found a great Sword with something like 30% bonus against Undead in the Furious Paladin's place. I didn't have the coins to buy it right away so I ran around on a killing spree leveling up and saving the cash to buy the item.

Tonight I was ready to buy the Sword and ...lo and behold...the thing is gone.

Now I know that no one else could have bought it of course. So where did it go?

Basically I wanted to find out if there are expirations on items seen for sale. Do they disappear after a while? Do they show up in other places or do they vanish for good? I was pumped to go on a nice quest in the crypts, but now there is no chance I have the power to do so anymore without that (or another) Undead bonus item.

Can anyone give me some feedback on this mystery and what to expect in the future?

Cheers to the designers of this most beautiful work!