A local guy says with wire basket trees, their team can do them in 4 minutes each, once they get going. Whew! Lot of prep, and I think a team of 6 with 3 vehicles.
However planting someone else's trees is a bad bet. If a tree dies, you say, "Bad tree" Tree farm says "bad planting" Lot of finger pointing. Result -- unhappy customer. You will get some of the tar from that mess.
Either provide the trees yourself, or subcontract with the provider to plant. Key feature: Someone who owned the trees supervised the planting so you don't get holding the stick if they die.
If you buy the trees and resell and plant, then be sure the seller will warrant the tree. Suggest that they send an observer out to watch you plant the first few if this is the first time you have dealt with them.