John,
If you have a functioning one, I would definitely be interested!
Griffin.
I found a SB-28DX in my "collection." It is one I used in the early digital days. It has the pouch, box, instructions and is in very nice cosmetic condition. I have put batteries in it and it seems to work well. I'll give you a ten day return privilege to make it sure it meets your needs and expectations. My guess is that $50 is a reasonable price plus whatever it costs to ship it to you. I see you are in the US so it won't be any more than $10 for regular USPS.
John White
www.aiconversions.com