All hobbies are now seen as 'marketing opportunities' and a large industry has sprung up to convince us to buy expensive and useless pieces of kit.
I used to go to the Bird Fair, the birdwatchers equivalent of Aerofair and there you could buy anything for the discerning birder.
There were stands selling the essentials such as binoculars, telescopes, tripods and field guides, al the way through to useless things such as electric heaters for your bird bath! And people fall for the line "this piece of kit is essential for today's birdwatcher", when its just not true.
PS - I,vejust ordered a GPS III for less than £300 inc VAT, Garmin are ceasing production of GPS3s soon.