The constraint that governs everything is blade diameter. It sets the size of root ball the machine can take, and therefore the largest trunk it can safely move; too small a ball relative to the tree is the single most common reason a transplant fails a year later. Species, season and aftercare do the rest, which is why the operator's judgment matters as much as the machine.
Post the job with the tree's trunk diameter, species and both locations, and tree spade providers whose radius covers you are notified. Providers list the machine they run, so you can see the blade size before you message — the first question anyone will ask you anyway.
A tree spade earns its cost when the alternative is losing a tree that took twenty years to grow. Development that clips a corner of a mature planting, a landscape being rearranged rather than replaced, a nursery moving stock, a specimen a family wants to take with them — in each case the tree already exists, and buying its equivalent at that size costs many times what moving it does.
The judgment you're hiring for is whether a given tree should be moved at all. Species tolerance varies enormously, a tree stressed by drought or recent construction is a poor candidate whatever its size, and root systems that have spread under paving rarely come out whole. An operator who tells you a tree isn't worth moving has saved you the cost of watching it die in its new hole two summers later.
Pricing usually covers mobilization plus a per-tree rate that scales with blade size, and moves within one site cost less than moves between two. Aftercare is the part that gets left out of quotes and decides outcomes, so establish who is watering, how often, and for how long. As with every service here, the terms are between you and the provider.
For providers, spade work is specialized enough that most tree companies have no idea who locally owns one. Landscapers, developers and nurseries all generate this work and none of them have a good way to find you. Put the blade diameter in your profile — it is the single specification that decides whether a caller's tree is even a candidate.
Transplanting is seasonal in a way most tree work isn't: dormancy governs it, so the calendar concentrates demand into two windows. Set your radius wide enough to catch a whole region during those weeks, and use travel dates when you're taking the machine somewhere for a project — you'll appear in searches at the destination while you're there.