A few years ago I bought some seedlings of Green Sapote (Pouteria viridis) from Roger Meyer. I've been propagating them in 15 gallon pots and training them for production. They are currently about 1" diameter caliper and about 2 feet in height above the soil line with numerous side branches.

Since there are many entrepreneurs here, I'm wondering what is the base price I should offer these plants on eBay or similar. Your advice is appreciated!

I'd start one out at $.99 like I do with all of my things and let the marketplace tell you what it's worth.  Every once and a while things will go quite cheap but not too often.  I worry more about getting enough sleep than the prices.