Consider the Tennessee Department of Forestry hybrid Chestnut seelings. I think you will find they are a lot like the Dunstan. Dunstan is a patented name that can't be used by others. It's kind of like buying generic versus brand name.
I did that last year ordered a hundred. There survival rate was maybe 25% to this point. Many had the tops die but the bottom branches still are alive. I planted a 100 sawtooth with them alternating every other tree and got 90% survival out of the sawtooth so I'm not big on the TN forestry chestnuts. The dunstans have done good so I guess I'll wait till next year to plant what mine produce again. I need to many to pay 25$ a tree... Lol
Spend your time where you get the most return on it...