May or may not fit your specs, but for a wide variety of species, at affordable costs, check out OIKOS Tree Crops.
Good selection of oaks, nut trees, and native fruiting trees, as well as other oddball stuff.

I've ordered various things from them for years. Mostly small, paper-pot-grown stuff, but have, in the past, bought some larger field-grown specimens. Some may be spindly when they arrive, but they bulk up and grow just fine - and the prices are reasonable.

Here is a link that might be useful: OIKOS

3 to 5 foot trees mail order???

for under 10 bucks..

these must be bare root??? yes???

if so.. isnt it a bit late to be contemplating such in your zone???

ken

Cold Stream Farms has some really cheap trees. I get them there all the time.

Here is a link that might be useful: Cold Stream Farms

Forest farm is my benchmark for quality unique trees.

Want a dozen generic redbuds and I start looking to Musser forests.

Does your state have a seedling program? Few years back I ordered a bunch of dogwoods from our DNR to practice grafting on.