I believe that it is a conflict of interest for a consultant to advise on what tree works are necessary and also to price the works.
After many years working as a tree surgeon and then as a consulting arboriculturist, I have been dismayed to come across many situations where tree owners have been given poor advice by bogus (or even bona fide) tree surgeons which has resulted in unnecessary and expensive tree work and/or badly executed or excessive work that has resulted in disfigured trees, their slow demise from disease and decay and sometimes locking the tree owner into a cycle of expensive maintenance of weakened trees.
Whilst there are genuine tree surgeons around who will give a free, honest opinion on your trees, and may talk you out of expensive work, the only way to be sure if the work is needed and to be able to have comeback on poor advice is to get an objective opinion from an independent arboriculturist who has nothing to gain financially from whether expensive follow-up work is needed.
And if work is needed, I can produce a clear specification, find and appoint the most financially advantageous contractor and supervise and sign off the tree work. Although this all comes at a cost, it can save money (and could save your tree) to do it properly.