Item ID Range by Expansion
 

Anyone happen to know or know of a way to determine item id ranges for each expansion?

That is something you would have to do manually. I am sure you could look through the table and identify the cut off for each expansion by comparing what gear comes from each expansion and narrowing it down. Though, I am sure that wouldn't handle 100% of what you are asking to do. Some stuff was added to previous expansions after newer ones were released, so some would need to be done manually on a case-by-case basis. This would be quite a task to undertake.

You may be able to automate some of it out by doing some data mining of sites like Zam and Magelo, but I don't think that would be an easy task either.