I'm relieved, and a little amused, to find that "the old tour agency game" that I played so many times back in South America, can be played here in Thailand as well. And the rules are virtually identical, too. Here in Chiang Mai, it's the usual setup: there are a hundred different agencies, all offering similar activities, and all quoting slightly different prices. But in the end, they all ring up exactly the same people who actually run the tours, and they all send you on exactly the same tour; and really, it's all exactly the same thing. So you may as well just visit 5 or 10 of them, pick the one that quotes the cheapest price, bargain them down further still, and go for it — because the price and the agency doesn't matter in the slightest, it's all the same tour. Thailand also operates by the standard "book when you get there" rule: it's cheaper to book things when you arrive in Chiang Mai, than to book them from Bangkok (same as booking in Cusco vs Lima), as more cities away only means more middlemen, each of whom will take a cut as they call the next friend down the chain. C'mon, Thailand: you think I started backpacking yesterday, or something? I know this game, you don't fool me!
I played the tour agency game today, in order to book the Doi Inthanon trek that I'll be starting tomorrow. Doi Inthanon is the standard trek out of Chiang Mai, and it's the most popular and the most mass-market of all the treks on offer in northern Thailand. As such, every agency in town is offering it, and there's plenty of competition to choose from. But I'm not stupid, I realise how it's set up: none of the "tour agencies" are real agencies, none of them actually run any tours themselves. They're all just middlemen between you and the actual (ever-mysterious) tour operator, and they're competing with each other for little more than a small, highly-negotiable commission on their part. I booked Doi Inthanon, no problems — so tomorrow, I'm off.