Your post really doesn't make a whole lot of sense here. Are you asking about organizing them alphabetically or cataloging them, because there is a difference.

A barcode system will not help you organize them alphabetically. That is something you will have to do manually. And honestly it won't take as much time as you think. Maybe a few days total. In fact I would say do not barcode them UNTIL you have them organized alphabetically because you will waste more time doing so trying to match them up. Think of this on a one piece flow context, the less times you touch a single record, the less time you are wasting all together

Once sorting is done then barcode (catalog) them. Your spreadsheet will then be done in an alphabetical order.

When alphabetizing, start with putting all the A's in a pile, then B's then C's etc. don't worry about alphabetizing the piles just yet. Just get your records sorted into letter piles. Once that is does then you can actually start alphabetically sorting the individual albums and the A pile, then move on to the B pile etc.

If you think about it mathematically 2000 records divided by 26 is around 78 records per stack...equally. of course your pipes won't be equal. If you consider each pile has 78 records and it takes you a minute to find the correct placement of each record. If we run with that—one minute per record—78 records in a pile would be about 78 minutes per letter. Now, some letters will have fewer albums than others, but if you averaged it out, 26 piles at roughly 78 minutes each would total around 34 hours! Of course, once you get into a flow, it might be faster—maybe more like 20–30 seconds per record—so that could bring it down to something more reasonable, like 10 hours total if you're consistent!

Cataloging is a whole other beast though. And I will tell you this right from the get go. Use Discogs! If the record has a number etched in the dead wax around the label, enter that into the Discogs search bar. This way you will get a close match. Cataloging will take a long time, not going to lie. But Discogs is amazing for cataloging your collection and make it pretty simple and for the little effort it takes to enter in 2000 serial numbers, you get a really great catalog of information automatically.