Not so much about loyalty as it is about reciprocity...or convenience. The falconer is basically a large walking refrigerator of meat, and has to learn-and-walk a fine balance between keeping the bird hungry enough to fly and hunt (necessary for upkeep of muscles and skills), vs satisfied enough to know that the falconer represents a guaranteed meal.
Nothing like a dog, perhaps more like a cat..only even more independent.
Cost depends on the type of predator bird one gets, and how rare or difficult they are to catch and/or breed.
For example, the costs of some of the more rare he mentioned $13,000, while for a common kestrel was about $400-$700.
I don't know how much the upkeep of being a falconer is yet, not even a ballpark figure.
(Normally I would be looking this stuff up to learn as much as I can as quickly as I can, but I've been in the middle of a project that's taking a large amount of my mental faculties.)