To claim that there's a significant number of transgender people out there like this is simply ridiculous.
I've only encountered 3 in my life, and two were from people I know who had the exact situation I described happen. I think for both it was just kind of a date that didn't last longer than a few minutes.
Tip: look for an Adam's Apple.
That's just cartilage, isn't prominent in all men (and is even prominent in some women) and even failing that it's not terribly expensive to have trimmed. Considerably less expensive than a boob job and even less expensive than bottom surgery.
In my actual experience, hand size is the biggest giveaway, followed by voice, and occasionally you see that their breasts look too far away from their shoulders (because their shoulders are too broad.)
I remember going to this bar and this tranny with really big tits walked by, but then he spoke as I watched him grab his drink and my first thought was "no."
Neither hand size nor shoulder width are terribly apparent in pictures though. I guess it's like buying a used car that looks good in the picture, but when you get up close to look at it, it has a shitty paint job.