I don't use barcodes, but only sell through a couple of retailers. One retailer has developed a "code" that they use on invoices that identify the product. (LOSTRCAM = Lights Out striker camo) I don't know if they use a barcode as well, but I haven't paid for any.
I checked into it several years back as well. Building calls in a one man shop after I get off work and on the weekends just doesn't make it an option for me. One thing you might want to think about as well - Most retailers will require 40% of the selling price of the call as their cut. In other words, if you sell your calls for $50, you get $30, they get $20. Unless you can really roll them out, get your materials at a reduced price or just don't value your time much, it's hard to make money when you build them one at a time. Just a thought.
