I think your going to be challenged with the mods, mileage and year of the rig. As you probably know, bone stock trucks go for higher. For example, I bought my '97 two years ago with 85K miles, from Arizona (read zero rust), for $24K. Completely stock.
But it's hard to say. You could luck out and find someone who wants what you have at your price. That's the beauty of it all...
If your committed to selling it with the goods, I'd say start at $25 and see what offers you get. Really all depends on how long you can wait to sell it. I would start at 25 and wait a few weeks.