Assuming you are doing the work yourself and already own a shovel, the cost to plant a tree would be limited to the price of the tree itself, plus the costs of the stakes, if needed, and strap material. If the soil is rocky where you live, you may need to invest in a pickaxe (about $40) to help with the digging process. Also add in the cost for a 3- to 4-inch layer of mulch about 4 feet out around the tree.