Compare Several Hundred Rows Against Other Rows

Not sure if what I want to do is possible, or at least possible the way things are set up.

I have a massive table - c. 6 million rows. It contains data along these lines:

Plan#, Item, Price, Description, Colour, Value, Location, etc.

The primary key would be Plan# + Item. Each Plan# has approximately 1,000 Items, and there is only 1 Item per Plan#. There are only a limited number of Items (c. 1500) and all or only some Items might be assigned to the Plan#. All items under each unique ID# belong together, sort of in a set. So this huge table has approx. 6,000 unique sets (based on Plan#).

To add to the confusion, Item A under Plan#1 may have different information (Price, Description, Colour, etc.) from Item A under Plan#2. I know this isn't a great way to set up data but this is what I have to work with.

Over the years it's possible that the exact same combination of Items with identical values might have been set up for multiple Plan#s. What I need to do is find any Plan#s which have the exact same combination of Item, Price, Description, etc. So if Plan#R has 200 rows and Plan#S has 201 rows, it automatically doesn't match. If Plan#R has 200 rows and so does Plan#T, all information in each record must match between the two Plan#s (with the exception obviously of Plan#).

I don't think this is possible, and if it is I am sure it's not going to be easy. So far the best I can do is to come up with finding duplicates on Item, Price, Description, etc. but that's only one record at a time and doesn't tell me if the two Plan#s match.

Any help or suggestions would be much appreciated.

Thanks!!!