I've been looking into this for a while and much of it depends on so many variables that it seems impossible to put a fixed sum to it, but as an idea:
Bird: £150 to well, the sky is literally the limit.
Mews/Aviary: Depends on the bird and your DIY ability £200+
Telemetry: £500 new
Dog/Ferrets: again depends on the bird, the style of hunting that you want to do and what you've already got.
Freezer: £150
Scales: £20
Bow Perch: £50
Bath: £25
Hawking Vest/Bag: £30+
Glove: £25+
Misc Equipment (creance, lure etc): £100+
Whiskey for the landowners at Christmas: £50+
Time