My gut instinct is the tree is over 20 years old.Maybe even over 30 years.

Of course you don't tell us how TALL it is..so it's a guessing game really.

My guess was in that range also.

I planted an 8’ autumn brilliance service berry 7 years ago. It’s about 9-10’ tall now.

Get the biggest one you can afford and take good care of it with proper planting & watering the 1st 2 years. You’ll love it! My favorite time of year is when the cat birds come to dine on the berries in June. They talk to us when we get too near in the yard & it’s hilarious bc it sounds like “get away while I’m eating!”

Umm, not specific to serviceberries (of which I've grown three), but I would almost argue get the smallest container grown tree you can find from a local grower/native plant seller.

The problem with a larger tree from a commercial source is transplant shock from root loss (as they cut the roots when digging) and it takes years to recover and get going again.

I've often found that younger trees that haven't had that terrible trauma (and hopefully are not root bound) actually will make better growth than the big one that was in poor condition to start with.

Neither is going to be a growth speed demon though, as you may have guessed from above. This is a tree to plant for your retirement in your forever home or for your children to enjoy.