I might also want to create my own website for direct sales rather than using ebay, so managing the inventory and sales details would be better via my own database. The problem is, comic prices are variable and that is what is so great about CPG.  Put in your inventory and the prices are mantained automatically.

So, my goal is to create/use an application to port the data to another database as well as use the application to periodically obtain the latest prices from CPG for each of my collection's titles. To do this, I need to create a unique code for each individual title from the fields provided by CPG in the download file (since no unique field is already provided in that file). 

Right now I am considering using the PUBLISHER + TITLE + VOLUME + START YEAR as the unique field. Does it seem reasonable to assume that a publisher would not release the exact same title during the same year with the same volume number?

By the way, I will make this program available for free to everyone when it is done.  This program should be seen as complimentary to CPG since it still requires the CPG data (and likewise the subscription) in order to use it.

^{YOU WERE POUNCED ON BY THE BIG-CAT!!}

You're talking about a key, like the same with Microsoft access database. Correct?  (a key that is unique)?

^{YOU WERE POUNCED ON BY THE BIG-CAT!!}

UPDATE comics SET qty = qty-1 WHERE titlekey = 'MALIBU_RUNE_1_1993'

(the Title Key being Publisher + Title + Volume + Start Year)

In the new database I am developiong, I am dividing the CPG Title field into separate Title, Volume, Start Year, and All Years Fields and I am adding the "Title Key" field as well as dropping the "Subtotal" field (i.e. qty * price) because it can be calculated at any time.

My program will convert the CPG Excel file data so that it can be imported into an Access database and then the program will be further used to periodically extract the latest prices from newer CPG downloads by parsing the new Excel file using the original parsing algorithm. Of course the downside is that I have no control over any changes to the layout of the CPG Excel file that may occur over time, but I can always update the program pretty easily if need be.

The net result is that I will have a local database that has all of my comics with the latest prices and as I sell them I can manage the ever shrinking inventory as well as the boxes where the comics are located (which also will change). And, I might even create an E-Store of some kind and sell the comics directly at X% off of book price using an Access database that utilizes dynamic inventory reduction.

I have 18,000 comics to sell and it is going to take a while to do.  So, I am trying to take advantage of the power of CPGs pricing model while still taking advantage of my own programming skills in managing the sales and inventory aspect of this project.

Sorry for the longwindedness... I just wondered if people thought that I could get away with a key for the title being Publisher + Title + Volume + Start Year...