I'm using Groovy for scripting. It's a scripting language that runs on the JVM, so it performs just as well as regular Java code. And, because it's running on the JVM it's very easy to integrate, no messing with creating bindings and such.

I've had some similar issues, at one point if you bought a whole lot of a very expensive item, the cost would actually flip, and you'd get money for buying stuff. Fun stuff!

Ah, sorry for the random question, I have actually never worked with java, other than helping one of my friend's with his uni work (he was converting A* from c++ to java (though I was sure there is a java rendition XD))

And yea I've encountered those problems a few times, though as mention the dransik "money" bug was amusing, and it was it that lead to you being unable to buy more than 50 stackables at any given time (minus sold item's whcih stuck to 10 (always found that weird)).

I must agree though, having bug's to find it always fun, it's the fixing them that is the pain XD, though depending on how severe the bug is.