I just sold my
BX23 - using Craigslist.
I had the same problem: trying to determine pricing. The number of
BX23's out there for sale are few and far between - and most of them had far less hours than mine did (616 hours).
Here's what I did : I searched Craigslist nationwide by using sites like
allofcraigs.com - Search ALL of Craigslist - and I found a few tractors for sale there. I also searched Ebay and places like Tractorhouse to see what was for sale. If you do all of that - plus search around on some of the other tractor sites you should be able to come up with 4 or 5 tractors like yours for sale. From what I have seen - 200-300 hours is pretty much normal time for a tractor of that vintage. If you've got all the maintainence documented then that will definitely help.
Just so you have some idea of how the deal might go down - here's how it worked out for me. My BX had loaded tires, a toothbar, 12" bucket on the backhoe - and a clamp on thumb on the backhoe (barely used). I priced it at $10,750. I also had the factory Workshop Manual, a 60" rear blade, and a 24" bucket for the backhoe - all of which I was going to sell separately. The dealer offered me $6500 on the trade in. When the Craigslist ad went in -I had four emails within a couple of hours. That was on a Sunday night. I had three people look at the tractor on Monday and Tuesday - and 3 more people who were offering my $7k to $8500 sight unseen. One of my initial responses was from a guy who was coming down from New Brunswick (I'm in MA) - and he sounded like the most promising one because he sounded serious. He showed up on Wed, looked the tractor over thoroughly - and offered $10k - with the rear blade, manual - and 24" bucket. I figured I would probably end up with about another $600 or so from selling those three separately.
So - my suggestion would be - do your research and find what you think is a good price point - and go a little higher (like $500 to $1000), clean up the tractor and make sure everything works. Get all of your records, etc. The put it on Craigslist. And take some good pictures - I had the Craigslist max of four - plus a link to a bunch more on my Photobucket site. So people could get a complete picture of what the tractor looked like.